This tutorial was made in GIMP. It should translate.
go from this
to this
first, take your base, duplicate it and set it at soft light, screen, whatever until you have the right brightness.
I flatten all layers now.
now, make a new layer, fill it with a blue color. I used 0082bd, set the first layer to addition, then duplicate it and set this one to difference. You can also just have one layer and set it to exclusion if you have it.
Duplicate your base layer and set it to soft light at around 40-50% opacity.
Now, go to tools->color tools->hue/saturation.
at the top, select one of the colors on the color wheel, like red, I usually up the redness like I did in this pic and then the cyan and blue. This is now your new base layer.
Now, add new layer, a plain white layer, and set it to lighten at about 15% opacity.
Now, duplicate your base layer, up the saturation more if you want, and set to Color. I set mine to 66% opacity.
Then, flatten all layers, sharpen, and there you go.
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