That you find 'yellowarse' insulting is more an indication of your own perverse conditioning and self-loathing than of a lack of self-esteem on my part:
Yellow is inferior to white in your internalized racist worldview; and arse refers to a part of your anatomy you find disgusting. Ergo, yellowarse is derogatory. Ergo, I must hate myself to have adopted this moniker.
I, in the other hand, see yellow as one of seven colours in the rainbow - a beautuful metaphor for diversity; and arse as simply a humble organ that all humans possess and none can do without - in other words, an utter necessity.
See how your chain can be yanked by such an innocent nick?
Piece of advice: prejudices exacerbate your dysthymia, aggravate your irascibility, and heighten your sense of injustice at the world around you.
Take a deep breath, and let go. Peace.