We use the Supply theme. My Search Box looks like this when viewed in desktop size and you can see that the colors in the search box originate from Header section-> Text and links, and in Cart button and search field.
Theme Settings Colors are:
and in Chrome, inspecting the CSS shows
Making entered text almost invisible against the background color
The problem is with entering text into the search box in mobile view as it shows as too dark.
It is getting its color from theme.sccs.liquid (approx. ~line 1729):
which I believe is set by this particular Theme Color setting. Text->Body
You can barely make out the search term of "tap wrench" against the blue background.
|54 seconds ago|