When you pick up color and everything you know falls apart

Every time I step outside my graphite comfort zone and try to add color to a drawing, it feels like my brain short circuits. I can construct forms, I can lay down confident lines from the shoulder, I can work through a full page of boxes and cylinders without flinching. But the moment I pick up a colored pencil or even a simple marker set, all that confidence just evaporates.

I genuinely do not understand how color works in practice. Value I get, that's just light and dark. But choosing actual hues, making them sit next to each other without looking muddy or cartoonish, figuring out how warm and cool temperatures play into a form. It's like learning to draw all over again from zero.

For those of you who came from a drawing background and eventually got comfortable with color, what actually helped it click? Was it studying color theory formally, or more of a "just start filling sketchbook pages with bad color studies" kind of path? I'd honestly love to hear what the early stages looked like for you.