Ever since some new default colours were introduced, we haven't got any of the new colours for the GST butt taunt. The only colours that work with changing the colour of the taunt are default, but not all of them work. This is a problem for my Fox character, as his butt should be orange. It is unfair all the human avatars get their skin-coloured butt.
For reference, here are all of the colours the butt can't change to from the glove colour picker, marked with a cross. Those without a cross change the butt to that selected colour:
If a developer is reading this and it seems like a lot of work, please at least add the orange color!