Go from this
to this
Included
*Selective color [sorry for Psp user, just Ps]
*Curves
Ok, first of all, resize and crop your icons. I didn't sharp my and no screen layer.
Here your base
Duplicate your layer and fill it with yellow - I've used this [#ffff40]. Set on soft light
Now, go to Layer, new adjustmen Layer, selective color
REDS
cyan: -100
magenta: +100
yellow: +100
black: +0
YELLOWS
cyan: -29
magenta: +38
yellow: -32
black: +17
NEUTRALS
cyan: +100
magenta: +15
yellow: +12
black: 0
Another Selective color
REDS
cyan: -70
magenta: +30
yellow: +35
black: +0
YELLOWS
cyan: -21
magenta: 0
yellow: +23
black: 0
NEUTRALS
cyan: +42
magenta: -20
yellow: -20
black: 0
Again...Another Selective color
REDS
cyan: -100
magenta: +22
yellow: +24
black: +0
YELLOWS
cyan: -50
magenta: 0
yellow: 0
black: 0
Now, go to Layer, New Adjustement Layer -> Curves
RGB
I: 119 - O: 136
RED
I: 115 - O: 126
GREEN
I: 113 - O: 125
BLUE
I: 120 - O: 141
If you want, now duplicate the layer and set it on screen -> 25%
You're done
Other Icons made with this technique