I am restoring some old photos with colour casts etc.
In Affinity Photo I can apply a Levels adjustment then select the individual RGB channels and adjust the white and black sliders to touch the top and bottom of the specified histogram.
Try the white balance, by putting the pipette on something you know to be neutral black, grey or white. That is assuming you are dealing with a RAW file
Your old photos, are they scans of the originals (i.e. they are RGB images), or are have the originals be re-photographed, i.e. you have RAW files)?
If the latter then as @Joanna has said you can use the pipette in the’ RAW White Balance’ palette to sample something in the image that should be a neutral colour. You can then tweak the ‘Temperature’ and ‘Tint’ sliders if necessary.
To set the black and white points you can use the ‘Tone curve’ or use the ‘Spot weighted’ option of the ‘DxO Smart Lighting’ palette to sample the brightest and darkest areas of the image. The tone curve lets you tweak each of the RGB channels
If you only have an RGB image then while the ‘RGB white balance’ also has a pipette, you can only tweak that on the blue / yellow axis, i.e. you can’t adjust the tint. You can also use the tone curve and DxO Smart Lighting as already described for RAW files.
If you want the same kind of process, curves in v8 should give you the same result as levels since they have “black” and “white” points in and out (abscissa and ordinate) and gamma. And you have RGB individual curves.
May you confirm gamma still exists on individual color curves ? (I do not have v8).
here again curve tool (luma) should give you precision you need. Pipette should let you easily find the tones where to act or block.
If I understand what you want here, unless this is related to individual R G B channels in which case color curves above should do what you want.
And you can save preset to reapply if your series are homogeneous.
In v8 curve tool seems fully extended and should give precise result for lot of needs.