Given a Texture and an
y coordinate this method will return a new
Color object that has been populated with the color and alpha values of the pixel
at that location in the Texture.
The x coordinate of the pixel within the Texture.
The y coordinate of the pixel within the Texture.
The unique string-based key of the Texture.
|frame||string | number||<optional>||
The string or index of the Frame.
A Color object populated with the color values of the requested pixel,
null if the coordinates were out of bounds.