I've pointed in the direction of the Phrontistry in the past, but I thought I'd play a fun game this time:
there's a neato list of rarely used colour words.
I chose a couple favourite and googled them to find the first image that comes up on the search.
Here's my results:
Isabelline is "greyish yellow". That bird up the appeared on the top of the search likely due to the fact that it's a Isabelline Shrike.
The second colour I chose, coquelicot, is a brilliant, poppy red. Hence the poppy.
Wanna play too? It's fun!