[Emilee]

To change the colours and contrasts and stuff....
Once you have placed your pictures... preferably with the same type of background so you can blend them easily, and then click the merge button so they are all merged as one bit picture/banner.

Then click in: Adjust >>> Colour balance >>> Manual Colour Correction.

Then you can choose what type of colour you want and change it that way.
or...

Adjust> >>> hue and saturation >>>> colourise
or...

Layers >>> New Adjustment layer >>> and choose one of the colour changers in there.

Hope that helped on colour changing and contrast.