Simplify the following text for a Grade 10 native English-speaking person.
Original: This color-changing function is produced by groups of red , yellow , brown , and black pigmented chromatophores above a layer of reflective iridophores and leucophores , with up to 200 of these specialized pigment cells per square millimeter , which corresponds to about 359 DPI .
Simplified: This color-changing function is produced by groups of red , yellow , brown , and black pigmented chromatophores above a layer of reflective iridophores and leucophores , all of these being parts of the cuttlefish 's skin which help it change its color . There are up to 200 of these special pigment cells per square millimeter .