Issue with colour swapping header

[homeware75]

My header menu and icon colours are black instead of white and I have no idea why, looking at the code they are being set based on a colour variable, which itself is changed based on shopify background 3 setting, there is no background 3 in the settings, only 1 and 2. It works fine on the demo theme linked below.

Searching for the variables in VScode shows no results, its as if the background 3 colours variable doesnt exist in the code or in shopify settings. Most issues im able to figure out with inspect and code searches but this one has stumped me for hours, not a clue where to go to fix it. Site staging and example theme linked below, see how theirs changed from white to black text, but mine is set to black then a slightly different black. But again the place this is being set to 0, 0, 0 doesnt exist.

https://aytpcjqdumlwp6pg-77585907995.shopifypreview.com

https://themes.shopify.com/themes/minimalista/styles/graphite/preview