This is a little tutorial i whipped up in my spare time for very blue pictures. It doesn't work much with ordinary colored pictures, the result will be bright red :O So keep in mind it's 'potential' is 'limited' ^_^
1. Duplicate layer and set to screen 50% or to likeing
2. New adjustment layer > color balance (it's your friend!)
Shadows: 0 0 -40
Midtones:+21 +9 -32
3. New adjusment layer > selective color
Reds: C:-100 M:+100 Y:-100 B:+100
Yellows: C:-100 M:+5 Y:+9 B:0
Neutrals: C:-8 M:0 Y:-20 B:-7
4. New adjustment layer > selective color
Reds: C:-39 M:+21 Y:+55 B:+10
Neutrals: C:0 M:-3 Y:-13 B: -8
And ta-da, there you have it!