Obviously finding a new c&s that is unknown in any color supercedes a rare new color of a known chip. Personally I prefer USPC (espeially those in the records) over Burt chips.

Regarding your post:

For instance, the chips with the Masonic symbol: I have the yellow and green in this design and have seen these colors offered several times at auction. Are you considering only the red, white, and blue (shown in your post) as particularly rare?

Yelow and green are relatively common colors. A couple of years ago I received a group of USPC c&s from the son of a USPC worker. In the group were several chips I had never seen. The red, & white blue Masonic were three of those chips. Since I started collecting c&s, besides these three, I had never seen those colors. The fact that they were taken home by a worker leads me to believe these may be the only 3.

Second, I'm wondering if you are considering condition as one of the determining factors for rarity. For example, the Anona Cigar chips are often seen with one side well worn. I have two colors that are in this condition.

Look close Don. Your chips are very different from the ones I showed. I would not have shown them if they were the same as the ones Bud is selling.

Compare the two (rare one on the left):
I got the red and brown from Mark Freitag who, after accepting my offer, asked why I offered so much. I told Mark I had never seen that variety. Mark missed it, as I guess you also did. If it is a new find, condition wouldn't matter to me.

Finally, how about the CORTEZ chips. I have red, white, blue and yellow of this design. You show only the yellow in your rare-chip scan. Same question as above, is only that color especially rare?

Goot look closer Don. The common Cortez is the dark yellow/gold. The yellow is the only yellow I have ever seen (Steve P has the only lavender and John J has the only green)
Compare:

Bottom line is that color does matter, just not as much as a new club find.