In a previous photoshop tutorial, I gave an example of how to use the Replace Colour adjustment to change the colour of part of an image. In that example I used the sliders at the bottom of the Replace Colour dialog box to change a colour – it was pretty much a “guesstimate”. However if you want to be more precise about the colour you are using as a replacement, here’s a quick tip.
Once you’ve selected the area of colour you want to replace, click on the colour swatch, where it says Result, to the right of the sliders in the Replacement section. This brings up the Color Picker, where you can type in the exact CMYK or RGB value for the colour.