The value can be hex code, color name, or color array [r, g, b, a] (each component is in the 0 - 255 range).
If a color value (hex code, color name, or array) is provided, it is used as the global color for all objects.
If a function is provided, it is called on each rectangle to retrieve its color.
If a number is provided for radius, all the circles will have the same radius.
If an accessor function is provided, the function will be called to retrieve the radius of each circle.