This is just a small piece I'm going to use as my avatar. Please look for the full one as it is better.
I do know what you mean with contrast, the light colors are harder to see like this.
The bricks spelling out Rai were actually a blinkie, if you look under my gallery, you can see the full, animated piece where the letters light up.
Colors of hair, mushroom and sky are perhaps too close. Try different colors on the sky for better contrast.
The same with chocolate bricks and letters RAI - chocolate is dark and RAI is dark too. Maybe draw RAI in bright colors?
I do know what you mean with contrast, the light colors are harder to see like this.
The bricks spelling out Rai were actually a blinkie, if you look under my gallery, you can see the full, animated piece where the letters light up.