I'm looking for (phrasal) verbs that describe these two actions.
Imagine in a music concert, if yor're a guest singer that is invited by the main singer, you're usually going to want to dress less attractive/flashy than the main singer because you don't want to stand out as being more important and draw all the attention to yourself. So is there a verb/phrasal verb that describes "to dress less attractive or make yourself look less attractive", and a verb that describes "to make yourself stand out as being more important than someone else" or "make someone else appear less important/worse than yourself"? I.e.
He is […] because he doesn't want to […] the main singer.
Best Answer
He is dressed/behaving/acting unobtrusively because he doesn't want to [upstage] the main singer.
The synonym inconspicuously fits nicely too.
There are a number of words following that approach, each carrying different nuance, that may also work.
There are also words that better capture the relative aspect of the behavior but are less descriptive, such as deferentially.
The words suggested so far for the second missing word work, although if you are still dissatisfied with what you have I can think of a few more.