I hope this hasn't been addressed elsewhere - I read this thread and didn't see anything.

I'm using MultiMC 5 v.0.4.11-751 to create a 1.9 instance with Forge 12.16.0.1817, C&B 9.9, FCB 2.2 & JEI 3.1.2.172.

When I create a single player world, creative, place a dark red block #0, left click it with a diamond chisel, the block turns a sort of grayish blue.

Here's a gif: I picked a different block to make the color change more noticeable.
https://giphy.com/gifs/BSgNdnGPARzdm

I'm sorry if I missed something! Thank you so much for taking the time to create this for the community and maintain it! I'm really excited to use this on my first 1.9 server.

Fixed in C&B 9.10