As requested by
mizukipi, here we are with my first tutorial in this community :)
Open an image in photoshop. Crop it and sharpen if you want. I usually don't sharpen icons, but it depends on your personal tastes.
Duplicate your base and set it on Screen; 45%. Then go to Layer -> New adjustment -> layer selective color. In the red box set this values:
Cyan: -100; Magenta: +100; Yellow: +100. Then duplicate the level.
Now create a new layer and fill it with #a2d8f4. Set the layer in Color burn and duplicate the layer.
And the coloring is done! Now add some textures or brushes. I added a scratch texture [forgot the maker >_<]. And the icons is finished :) pretty easy, isn't it?