Create single utility type to encapsulate color argument

[joshuaellis]

Describe the feature you'd like:

Certain functions & properties have the type Color | string | number because they create a THREE.Color in the function and those are the arguments that THREE.Color can take, like the example below:

    renderPass: (
        renderer: WebGLRenderer,
        passMaterial: Material,
        renderTarget: WebGLRenderTarget,
        clearColor: Color | string | number,
        clearAlpha: Color | string | number,
    ) => void;

Suggested implementation:

Therefore we want to create a utility type so instead of typing Color | string | number we only need to write one, this would then need to replace all instances of the previous type across the codebase.