Seems impossible to color match via pictures taken by different cameras in different lighting -- the data needs to come from people who can compare the products side-by-side.
Maybe a color-coded table like
this example for each major color (red, dark blue, light blue, yellow, green, orange?, purple?) with a list of products on the two axes.
A black background indicates that the row and column are the same item, grey means that the data is not yet available, green means a color match between the row product and the column product, yellow means a close match, and red means that they are not close to matching.
If you like, we can also add footnotes/links to photos in the table, too.
The new wiki page linked above is currently an orphan page, but if we go forward with building it, the
Finishing and Artwork portal page may be a good page to direct readers to the color matching page.
Scott