I’ve been thinking about doing this for a while & started this I think a week ago & I quite like how it turned out. It’s basically an imagination of if Celestia were a metal guitarist & singer (she’d most likely do power metal & neoclassical metal). For the guitar playing one, I was thinking which band t shirt I should have her wear (within the power metal category) & thought of Rhapsody of Fire. Guitar pictured is based on a Jackson King V.  
I couldn’t think of many suitable colours for her dress tho but if you think it should have more colours & which ones, feel free to suggest some in the comments.
 
UPDATE - 26/09/2017: just scanned with printer so looks better & slightly brighter