bearisgray

The reasons why I am posting that site as a resource:

1) One can choose from six different background colors for the pieces while assembling them. I am amazed at how a background change can emphasize or drab the colors of the pieces.
Background colors - black or dark charcoal
muted eggplant or dark mauve
blue gray
medium gray
sagey green
ivory
white

2) That the color I "think" I am working with - isn't actually the color that it is.
Example: I "think" I am putting together a picture of a white cat - and the actual color of the pieces might be tan or pink or gray.

3) That the overall effect from lots of little pieces can be very surprising and not at all what one might expect. I have assembled several puzzles where the individual pieces look like ink scribbles - and when put together, it was a cat or a wolf.

So - Color A can appear to change color or value - depending on what is surrounding it.
The sum of the pieces can be unexpected and take on an image of its own.