I use colour graphics with foiling all the time, it's amazing. Like a bleach it depends on how dark the hair is for how light it will lift. I find they lift with a lovely tone and are softer than bleach foils.
I normally start with the 8 developer, then mix them both for 15 and then finish on 22 to get an even lift through the whole hair.
The different tones work to take away any unnecessary tones.
Green takes away red, blue takes away orange, purple takes away yellow, red enhances red tones and the neutral is just a nice creamy tone.
You can also mix the tones in together ( I do purple and nuetral a lot)
The green, blue and red work great for ombres too

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