Hi there, @lcarolan ...
The color scheme that you see within Canvas (on the left side global navigation) and the colors of the text within Canvas are all controlled in a "Theme" that can be configured at a Canvas administrative level. This means that the theme is applied throughout your school's entire Canvas environment...and it cannot be changed at a course level. Some schools also have a sub-account structure set up to separate out different programs or campuses, for example. Canvas administrators at your school can theme those sub-accounts with different colors, too. But, overall, instructors are not able to change the color schemes...as the themes are generally set with school colors and logos.
I know this might not be the answer you were hoping for, but I hope it helps to answer your question. Let Community members know if you have any other questions about this...thanks! Take care, stay safe, and be well.
