Document:

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                                                                    EXHIBIT 10.6

                       [COLOR KINETICS INCORPORATED LOGO]

June 28, 2000

Mr. Howard Rosen
RAK Group, LLC
140 West 57th Street
New York, NY 10019

Dear Howard,

In accordance with Section 32 of our lease agreement dated April 25, 2000,
please let this letter serve as written notice of Color Kinetics decision to
exercise its right to expand on the 10th floor of the 10 Milk Street property.
Color Kinetics has decided to elect the expansion option whereby we take
approximately 9,000 square feet on January 1, 2001 with June 1, 2001 being the
effective date for the remaining space on the 10th floor. These dates are
subject to the existing terms of the lease including the requirements and
conditions for substantial completion.

The Company has instructed its bank to issue the additional $1,000,000 security
deposit in accordance with the terms of our lease agreement. Please let me know
if you need any further information.

On behalf of everyone at Color Kinetics, we look forward to a mutually rewarding
and long-term relationship with RAK Group. Please keep us informed of future
expansion opportunities within the space as we are committed to making 10 Milk
Street our worldwide corporate headquarters.

Sincerely,

/s/ David Johnson
------------------------------
David Johnson
Vice President of Finance<PAGE>

                                                                    EXHIBIT 10.7

                          STORAGE SPACE LEASE AGREEMENT

           This Storage Space Lease Agreement (the "STORAGE LEASE") is dated as
of April 25, 2000 by and between RAK OLD SOUTH ASSOCIATES LIMITED PARTNERSHIP, a
Massachusetts limited partnership, having an address at 140 West 57th Street,
New York, New York 10019 ("LANDLORD"), and COLOR KINETICS, INC., a Delaware
corporation, having an address at 10 Milk Street, Boston, Massachusetts 02108
("TENANT") for storage space consisting of between 2,500 and 3,200 rentable
square feet of storage space (the "PREMISES"), located in the concourse level of
the building at 10 Milk Street, Boston, Massachusetts, in the location as shown
on Exhibit A. Based on the results of Landlord's permitting process with the
City of Boston, Landlord and Tenant will mutually agree as to the exact size of
the Premises no later than thirty (30) days from the date hereof.

         1.       Premises. Subject to the Landlord Work (defined below),
Landlord hereby leases to Tenant, and Tenant hereby leases from Landlord, the
Premises in their "as-is" condition on the terms and conditions hereinafter set
forth.

           "LANDLORD WORK" shall consist of constructing a demising wall and
door in substantially the location shown on Exhibit A, and leaving the Premises
in broom clean condition. If any staircase in the Premises is removed, Landlord
shall cap the area from which it was removed. At Landlord's own expense,
Landlord shall use commercially reasonable efforts to substantially complete the
Landlord Work on or before August 1, 2000.

         2.       Term. This Storage Lease shall be for seven (7) years
commencing and terminating on the same day as of the Lease Agreement between the
parties dated as of April 25, 2000 (the "MAIN LEASE") for the eleventh floor of
10 Milk Street, Boston, Massachusetts. Such term shall include Tenant's right to
extend the term of this Storage Lease for one (1) five-year period in the same
manner provided for in Section 2.5 of the Main Lease, provided Tenant exercises
the extension option under the Main Lease. In the event the Main Lease is
assigned, this Storage Lease shall be, at Tenant's election, either (1) assigned
to the same party or (2) terminated. This Storage Lease shall not be assigned
except to an assignee of the Main Lease.

         3.       Rent. Subject to Section 8 below, Tenant shall pay rent to
Landlord monthly in advance in the amount based on $15.00 per rentable square
foot per annum for Lease Years 1-3, and subsequently in the amount based on
$16.00 per rentable square foot per annum for Lease Years 4-7. Until Landlord
makes its final determination of the size of the Premises, Tenant's monthly rent
payment shall be $3,125.00, which payment shall be adjusted once the final
determination is made. The first such payment shall be made by Tenant on the
date hereof, although the period for which Rent is chargeable shall not start
until Tenant has received written notice that the Landlord Work has been
substantially completed.

         4.       Use. Tenant will use the Premises for general storage space,
miscellaneous shipping and receiving and as a prototype creation room and for no
other purpose. Tenant will use the Premises in compliance with all applicable
laws and shall not bring or permit to be brought or kept in the Premises or
elsewhere in the Building or Property any hazardous, toxic, flammable,
combustible or explosive fluid, material, chemical or substance including
without limitation, any item defined as hazardous pursuant to Chapter 21E of the
Massachusetts General

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Laws except for small quantities of household cleaning agents and the like, all
of which Tenant agrees to handle and dispose of in accordance with all
applicable laws.

         5.       Services. Landlord shall provide reasonable electrical
services to the Premises during the term of this Lease Agreement. Landlord shall
provide Tenant with usage and cost information from the applicable electricity
meters for the Premises and Tenant shall promptly pay the full amount directly
to the electricity provider. Landlord shall not provide cleaning, heating,
cooling, or any other services for the Premises.

         6.       Indemnity. Tenant hereby indemnifies and holds Landlord, its
trustees, directors, partners, officers, employees, servants, agents and
contractors (including without limitation its property managers, and any
affiliates thereof, and their respective officers, directors, trustees,
partners, employees, servants, agents and contractors) ("LANDLORD'S
REPRESENTATIVES") harmless of, from and against any and all actions, causes of
action, claims, costs, damages, debts, demands, expenses, liens, losses,
injuries, judgments, fines, penalties and any and all liabilities whatsoever, of
every name and nature, including without limitation attorneys' fees, whether on
account of injury to persons (including death) or property or otherwise, caused
by, arising out of or resulting from the use of the Premises, the building or
the property by Tenant or its employees, servants, agents, contractors or
invitees ("TENANT'S REPRESENTATIVES") or the conduct of Tenant's business, trade
or profession, or any activity, work or thing done, permitted or suffered by
Tenant in, on, or about the Premises, the building or the property, or any
breach or default in the performance of any obligation on Tenant's part to be
performed under the terms of this Storage Lease Agreement, or any act or
omission on the part of Tenant or Tenant's Representatives, excepting only as
the same may arise from the negligence or willful misconduct of Landlord; and
Tenant hereby agrees to and shall defend Landlord and Landlord's Representatives
against the same, at Tenant's sole cost and expense including without limitation
the payment by Tenant of the reasonable fees, disbursements and expenses of
attorneys, to be approved by Landlord, retained in such defense. This Section 6
shall survive the termination or expiration of this Storage Lease with respect
to any and all matters occurring during the term hereof, or any further period
during which Tenant shall hold the Premises as a tenant-at-will or
tenant-at-sufferance.

         7.       Tenant Insurance. Prior to occupying the Premises, Tenant
shall obtain and provide evidence of, and Tenant shall maintain during the term
of this Lease Agreement, the following policies of insurance:

                  (a)      "All-Risk" property insurance covering all present
and future articles of personal property and business machinery, equipment and
furniture and any improvements or betterments owned or installed by Tenant in
the Premises to a limit of not less than the full replacement cost thereof; and

                  (b)      Commercial general liability insurance with broad
form coverage with minimum limits of $3,000,000 per occurrence for personal
injury (including death) and $3,000,000 per occurrence for property damage.

                  (c)      Worker's compensation insurance with minimum limits
of $1,000,000 per accident and per disease per employee.

                                      -2-
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         On each of the above policies of insurance (but excluding insurance
with respect to Tenant's personal property), the following parties shall be
named as additional insureds: Landlord and RAK Group LLC, the managing agent.

         8.       Landlord Insurance. Throughout the term of this Storage Lease,
Landlord shall insure the Building of which the Premises are a part, and all
improvements which are considered to be part of the Building, against loss due
to fire and other casualties included in standard "all risk" insurance policies,
in an amount equal to 100% of the replacement cost thereof, exclusive of
footings and foundations, with a deductible per occurrence which shall be
commercially reasonable.

         9.       Waiver of Subrogation. Landlord and Tenant each waive and
release the other from any and all liabilities, claims and losses on account of
damage to personal or real property to the extent each is required to maintain
insurance pursuant to this Storage Lease or actually receives insurance proceeds
on account thereof. Each party hereto shall secure waiver of subrogation
endorsements from their respective insurance carriers.

         10.      Holding Over. In the event Tenant holds, occupies or detains
the Premises or any part thereof after the expiration of this Storage Lease,
Tenant shall pay to Landlord each Monday in advance one week's rent equal to
200% of the amount of the rent payable pursuant to Section 3 immediately prior
to such holding over period. In addition, Tenant shall be liable to Landlord for
any and all damages, excluding consequential damages, suffered by Landlord as a
result of such holding over. Such occupancy by Tenant shall be subject to every
other term, provision, condition, covenant and agreement contained herein.
Nothing contained in this Section 8 shall be construed as consent by Landlord to
any holding over by Tenant and Landlord expressly reserves the right to require
Tenant to surrender possession of the Premises to Landlord as provided in this
Lease Agreement upon the expiration of this Lease Agreement, to commence suit at
any time to recover possession of the Premises and recover all charges due
hereunder, and to apply payments received by Landlord from Tenant on account and
not as payment in full or in accord and satisfaction.

         This Section 10 shall survive the expiration of this Lease Agreement
and the term hereunder.

         11.      Access During Renovation. Landlord reserves the right to
access the Premises during the term of this Lease Agreement to continue
renovations. Landlord shall use reasonable efforts to minimize interference with
Tenant's operations in the Premises.

         12.      Miscellaneous. This Lease Agreement may be executed in
separate counterparts. This Lease Agreement shall be governed by the laws of the
Commonwealth of Massachusetts.

                  [Remainder of Page Intentionally Left Blank]

                                      -3-
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         IN WITNESS WHEREOF, the parties have executed this Lease Agreement as
of the date first set forth above.

                                       COLOR KINETICS, INC.

                                       By:/s/ David Johnson
                                          --------------------------------------
                                          Name: David Johnson
                                          Title: Vice President of Finance

                                       RAK OLD SOUTH ASSOCIATES LIMITED
                                          PARTNERSHIP

                                       By: RAK Washington Ventures Limited
                                           Partnership, its general partner

                                           By: RAK Washington Corp., its general
                                               partner

                                               By:/s/ Randy Kohana
                                                  ------------------------------
                                                  Name: Randy Kohana
                                                  Title: President

                                      -4-

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                                   EXHIBIT A
                                   Premises

                                [BASEMENT PLAN]

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