Mottled effect to undo monotony of a uniform colour...how ?

Hi,

CS6.

Looking at some artwork for aircraft skins for flight sims, what would be otherwise a perfectly uniform artifical looking area of colour has had a subtle mottled weathered look applied, like the clouds on a 10/10 cloudy day.

How best can this be achieved on a colour dumped with alt backspace from the colour palette into a layer ?

Ideally an ability to drag sliders to alter size of the mottle, variation in shades, introduction of a second similar colour maybe, etc.

On a side note, I also often need to add in the 'noise' we see when photographing a uniform colour and zooming in on it, as adding a colour to a photo edit, looks false, until the existing 'noise' is matched. A different method no doubt but again how is it done ?

Merlin