constructor(r, g, b, a) {
        this._rgba8Brand = undefined;
        this.r = RGBA8._clamp(r);
        this.g = RGBA8._clamp(g);
        this.b = RGBA8._clamp(b);
        this.a = RGBA8._clamp(a);
    }
A very VM friendly rgba datastructure.
Please don't touch unless you take a look at the IR.