[pbsd]

Why is SHA-2 orange? As far as I know, besides length-extension, there's no known weakness on the full hash function.

[chacham15]

https://en.wikipedia.org/wiki/Comparison_of_cryptographic_ha...

or more specifically: http://dx.doi.org/10.1007/978-3-642-38348-9_16 and http://eprint.iacr.org/2010/016.pdf

[harshreality]

The attacks are on reduced-round versions of SHA-256 and SHA-512. Those do not describe any attacks faster than (dumb) brute force against SHA-256 or SHA-512.

I think labeling SHA-256 as orange is highly misleading. The SHA-2 family of hashes is going nowhere unless the partial-round attacks get a lot closer to the full-round versions. They're still about 20+ rounds away.