A direct answer will require you to post a file.
Multiple things can control section color. The Display modes and “use section styles” - and note that when some options are grey’d out, they still affect appearance, so temporarily checking a box, changing a setting, and unchecking the box, can cure that. There’s a few settings here but going into further details is a waste without knowing how things are set up.
If section styles are enabled then you have to check the layer the object is on and set up a section style.
Clipping planes themselves can control settings and in some cases might override them.
And… object settings can override other settings (for example, ‘byLayer’).
But ya… a real solution is probably close at hand if you can post a file, even just a simple one.
