Very pretty ^^ It might benefit from being uploaded at a smaller size. The high resolution is emphasizing the grain of the colored pencil, and it looks a bit better when I click it to see at screen size. Keep the high resolution to yourself for printing :)

I adore how the flowers seem to glow, and the shading on the hummingbird's emerald feathers is lovely. The throat's feather transition is a bit abrupt; I can't pin down exactly what kind of hummingbird you were drawing to judge that properly, but the transition on the wings looks better to me.

The blue on the trees and hills helps the green and red hummingbird stand out, and especially if this is somewhere humid you could go further with it - more soft bluish-green trees and hills, greyish-blue from mist, dark sunset lighting. Right now the hummingbird's feathers are blending in a bit, having a brighter palette for the foreground and more muted/grey-blue for the non-sky background scenery would help. You have an opportunity to pick up on the violets in your flowers and beak with the shadowy areas (preferably not adjacent to the bird and flowers); right now it's a little strange that the light source area of your sky seems darker than the rest of it, and could perhaps use some darker shades of twilight on the right. The violets in the piece currently look amazing, on the beak / eye / in the flowers / claws, wouldn't want so much to distract from them of course.

Compositionally, something strikes me as a bit odd about the tree right behind the hummingbird's head, this might not have been under your control though. Otherwise nicely framed ^^

And this might be a good thing depending on perspective but your signature practically vanishes in the shady, dark line heavy spot it is located. Just something to note :)