Returns an RGBA color corresponding to the specified position and ordinal. This returns
a color cannot be determined for the specified position and ordinal. The specified
guaranteed to be one of the same Position references passed to a path at construction or in a call to
denotes the position's ordinal number as it appears in the position list
passed to the path. Ordinal numbers start with 0 and increase by 1 for every originally specified position.
For example, the first three path positions have ordinal values 0, 1, 2.
The returned color's RGB components must not
be premultiplied by its Alpha component.