I know how to use an image with a pixel brush to (for example) create a multi-colored stroke. I’d like to be able to do the same when working with a curve, such as a bezier. For some projects I need the mechanical precision that curves provide. How can I do that?
To achieve the result you want, what you can do is, make a vector layer, add your bezier curve, set a stroke with width and color in tool options, then select the vector layer add a stroke layer effect, then if you want to add another stroke over these, put the vector layer inside a group and add a stroke layer effect again.