Book cover colors... how are they added or chosen?

Okay I did some quick searches about this but all I saw was people asking on how other USE the data... so if I missed that information somewhere please just let me know. But I'm just curious, only two of my books from this years read piles have colors associated with them in my charts and graphs, so is it user added or is the data pulled from somewhere specific?

Thanks,
from a noob

I guess it's from https://www.librarything.com/coverguess ?

Probably not, as just a colour isn't counted.

>1 MiserableFlower: According to this post from when the feature was introduced, the info comes from Syndetics, a project that some LT staff are also involved in.

Note that the colors do not necessarily correspond to the colors of your own cover, or even in some cases the color that LT claims as the source (I think the latter case is when Syndetics changed the cover).