In order to improve our accessibility, we should strive to replace/tweak any unsafe colors for people affected by colorblindness. Red and Green (particularly in deuteranomaly) are often the colors most confusing for people who exhibit some colorblindness, but they are not the only hues. Our OpenRefine color palette was originally softly based around some early accessible color palettes if I recall like IBM Design Library (we choose mostly Blues, Greys, and Orange) which looks more or less like the "Contrasting palette 1" on this site.
But I think a few choices over the years might have skewed some of the original design philosophy? I think we should perform another colorblindness palette audit, in line with WCAG 2.1 AA standards as much as possible, to see where we can improve things. Also in doing so, that work can be incorporated into any upcoming new design system and documented in a design style.