This is a lovely picture to color. It has such pretty baby birds, choosing nice colors to color the baby birds will make the picture look really nice. First you can color the wood part of the tree with a brown, using a shade of brown that is good for a tree wood will make the picture look real. After that coloring the leafy part of the tree with green should be preferred.
All the leaves can be colored with a dark green or two different shades of green can be use like dark green and light green. The nest can be colored with a light brown shade.
The light brown in the dark brown wood will look pretty. The beaks of the birds can be of yellow color. The worm the big bird is feeding the baby birds can be colored pink and birds can be of yellow color.