[ksimmonds]

I've just finished taking photos of a school festival, and some of the photos I took inside (not all of them) have got a greenish tint to them. Is there an easy way to adjust the exposure for indoor artificial light .... after taking them?

[Medley]

Open the image, and go to Image> Mode> Lab Color.

Select the 'a' channel, then click the eye on the 'lab' channel. This lets you view the image as a whole while working on the highlighted 'a' channel.

Go to Image> Adjustments> Curves. Grab the top right-hand corner of the curve and drag it to the left. This adds red to offset the green tint. The further you drag the corner the more red you get. At some point, the image will balance out.

Dragging the bottom-left corner to the right adds green. In the 'b' channel, the top-right controls yellow, and the bottom-left controls blue. I mention this because you may discover you have a blue-green tint, rather than just green.

Hope it helps.

- Joe U.

[Etheryte]

I'd recommend using
Image->Adjustments->Levels,
Image->Adjustments->Curves and/or
Image->Adjustments->Color balance
depending on the image.