Nah, I'm just curious what he would actually change.
The multicoloured hair reflects the colour of bismuth itself, so I doubt that could go. You could changed the dreads to a multi-fade I suppose, though that might be annoying to animate.
The bulk is there and fits thematically, so that's not going to go.
I suppose you could give her a different outfit, but the current one is merely a bit plain, but not objectionable.
I have to admit, the grey-blue doesn't really work, but it'd be worse if it weren't a dull blueish colour due to the colour of the hair causing anything more vibrant to clash.
Everything is pretty much fine apart from the hairstyle (and eh on that, as I'm not truly convinced 'gummi dreads' doesn't work), and maybe a lack of accesories on the outfit.