Do the colors mean anything? I'm somewhat familiar with the 5. rating system, but not so much with colors.
Also, who rates the climbs? And is there ever any discussion about how well they are rated? "This 5.8 is easier than some 5.7's!" or "That was the hardest 5.10 ever! Shoulda been a 5.11!"
Also, I see that you have some A's and C's out there in the ratings... sub-ratings?
at this climbing gym (vertical world), the colors are just to mark what's "on" for a specific route. i guess i refer to them by colors/rating/wall to better identify them to myself. at seattle bouldering project, the colors correspond to difficulty (gray = easiest, then yellow, green, red, blue... i don't ever get above blue so i don't know the rest of the order).
i'm not sure who rates the climbs. i've been there when new ones are being set/just got set and the course setter leaves the label blank (5.--). maybe they have a couple experienced people climb and average what they rate it at?
and yes, there is definitely discussion about the ratings! i think it boils down to what you're good at/not good at. you might find an overhanging route with juggy holds (rated 5.8) much harder than a straight vertical route with crimpy holds (rated 5.10a), but someone with more upper body strength/endurance and less finger grip strength would feel the opposite. being on the shorter side, i often find routes that i assume were rated by people taller than me a lot harder than their rating when i get to a point where i have no idea how i'm supposed to get to the next hold (other than launching myself - which is a technique, but not considered the easiest). it's why i prefer outdoor climbing where everything is on and not just arbitrary-placed colored holds on a fake wall.
the letters are sub-ratings. i guess 5.10 used to be the hardest thing out there and they would distinguish between differences in "hardest" with the letters. but then people got better and they bumped it up to 5.11, 5.12, 5.13 (and apparently up to 5.15c) so it's sort of an open-ended system at this point.