Two different submitters, two different scans. Both are called brown. This is one of the weaknesses of a reference built by assorted collectors who have different ideas of color. I wonder if a better approach would be to solicit submissions for a single collector that revise the listings where apparent inconsistencies exist. I doubt the differences are intententional; most likely differences in scanners, scan parameters, and color vision of different submtters.

One specific problem is the selection of color names, especially ochre. Note what Wikipedia says about this:

Ochre (/ˈoʊkər/ OH-kər; from Greek: � χρός, ōkhrós, (pale yellow, pale), also spelled ocher, see spelling differences) is a natural earth pigment containing hydrated iron oxide, which ranges in color from yellow to deep orange or brown.

Some "ochres" and the natural pigments sharing the same name.