My first job for this community ^^
I hope you like it! I started to draw pixel art one week ago.
I appreciate any criticism.
EDIT: I just realised that it was intended to be a 4 colour challenge -- only noticed other submissions with the same colour scheme a few moments ago. My apologies.
This is a good attempt (especially considering you've only started a week ago.)
There is fairly good contrast between the ground and the tortoise itself. The addition of a shade of pink makes the piece less monotone than if you stuck with the orange and yellow.
I feel, however, that the specific shade of pink you chose for the sky does not seem to go very well with the clouds.
Hoping to see you make more pixel art for this community.