It's not bad, but I wouldn't say it's great either:
-Use official art of Dragonite to get a palette of its actual colours; you can do this by pasting a sprite into MS Paint and right click using the eyedropper tool, then use a brush to place the colour alongside the Pokémon you want to recolour.
-Repeat for all colours, even if you aren't sure you'll need them; you might for the outline
-Speaking of outline, you need to be aware of where your colouring looks clunky. For example, Porygon's left limb and nose need to have a green outline
-You should also vary the shades you use in your outline. The dark tan at the lightest part of Porygon's head looks awkward. Try considering where the light falls when choosing colours for your outline.