When I wrote my first paper, I experimented a bit with different colour styles until I found one that was both clear and aesthetically pleasing. I’ve since used it for all papers where I was first author. One of these submissions has been with a master’s student, who is now writing up his thesis.
He used the colour definitions from the paper for the figures in his thesis, which slightly irks me. Partly it is because this makes it harder to see which figures are cited from the paper and which are his own, partly because I put some effort into it. Is this so minor I should just let it go?
Update: As Wrzlprmft pointed out, using a consistent color scheme within a thesis is important for readability. Since recommending to use something and then requiring acknowledgement would be weird, I let it go.