Blend RGB Colors Using Gamma of 1.0

Have you ever tried overlaying one color on top of another and gotten dark fringing? That's because the blend math is being done after shifting the colors to a display gamma of 2.0 instead of blending THEN shifting. But theres a setting that fixes that that you can turn on.
Go to Edit ▸ Color Settings... ▸ Blend RGB Colors Using Gamma: 1.00

If you want to learn more, check out these links:
http://prolost.com/blog/2009/9/30/passing-the-linear-torch.html
https://www.youtube.com/watch?v=LKnqECcg6Gw