i dont think its a tick.
why would a tick want cold blood? or lock on where theres skull not juicy meaat? thats my reasoning.
is the scale hard like the rest of the head scales?
color changes could possibly happen if your ball is young. ive seen white spots but never gray like that. it could be something else im just saying make sure its a tick for sure before you try to pluck it off it could be something else. maybe use a magnifying glass?