It’s kind of tough with just one kanji…
I think 絵, which literally just means “a drawing” or “a picture” when alone as a word, would be a little bland unless the actual design was inventive. Something like 美 (beauty) would be a more typical single-kanji option.
Have you considered a yojijukugo (4-character idiomatic compound)? I know that’s a lot more kanji, but they are established words in a structure that Japanese people would recognize and appreciate.
Some related to art…
詩人墨客 (しじんぼっかく) poets and artists; persons who take delight in such refined pursuits as poetry, literature, painting, and calligraphy
創作意欲 (そうさくいよく) will (urge) to create; creative urge; appetite for writing
花鳥風月 (かちょうふうげつ) the beauties of nature; artistic pursuits involving nature themes
Or you could just browse more yojijukugo options.
If you got familiar enough with how yojijukugo are structured, you could theoretically try to put one together yourself.
I’m not ruling out a single kanji being a good option, I just can’t think of one myself.