Interesting style change! I like the angular shapes, it suits Rarity's hair quite well. I'm not sure if I like the background though; to me it feels too bright and saturated. The yellow is really throwing me off because it isn't used anywhere else in the piece. The blue and violet are ok as I do see variations of their tones on Rarity herself.
I can see you're really liking those watercolour brushes c: The effect is quite nice! And dat drop shadow
That's an interesting critique. The people in my stream while I was drawing seemed to really like the color choice. The reason I picked that yellow is because it's the violet in Rarity's mane's compliment. I would've made the whole rectangle behind her yellow, but that looked pretty uninteresting. So I put in some colors from her palette to tie it together.
And I do love my brush set~... I believe the particular one i used for coloring is supposed to be chalk though. In previous drawings I've achieved the watercolor effect by mixing and matching blending modes, using several brushes and washing out the colors. I don't actually have any brushes that are meant to look like watercolors.
Ah, I see what you mean about the yellow complimenting Rarity. Maybe it would have looked better if you had placed some yellow on the opposite side of your canvas, following the diamond shape you created with the blue.
Yes, yellow is her mane colour compliment, but in some cases compliments don't look right unless it is used somewhere else in the piece. I was just saying that perhaps the yellow could have been included somewhere else on Rarity, which would have tied her better to the background.