ColorCodes: eliminate NBS_ISCC sub dictionaries from lookups.

By their own documentation, the NBS submodules contain idiosyncratic
color names which are not well-suited to a general purpose color code
search.

In particular, NBS_ISCC::M contains a color called 'email' which caused
a confusing result for 'HTML email'.

The main NBS colors are included because they seem reasonable enough as
color names.

This fixes #490 and possibly partially addresses #454 and #442, I guess.
None that were particularly mentioned.  I think some of the comments about the trigger words needing trimmed back may be resolved by this, but none came with specific example cases.

I did see that the same dictionary contains a color code for 'wield'.. so this works:

https://duckduckgo.com/?q=wield+color

I didn't make any fundamental code changes, so I didn't know if there were other test cases I should include.  It seems a bit like cheating to come up with bad queries based on knowing which data I just excluded. :grin:

I'm certainly open to any suggestions for test cases, particularly if you run across them organically.