Brown-nose: I have read this word and was just wondering if 'brown' has something to do with the color of human stool.
Your nose is brown because you have shoved it up so deep -- you know where -- that you did not know where the boss ended and you started.
Am I right?
Sorry for the slightly vulgar tone -- what else does fit in the place of 'tone' here?
It was a case of 'for want of a better word'.

yes you've got the idea.