====== setShapeColor ======

  * Parameters & Types:
      * shapeid:number
      * r:number
      * g:number
     * b:number
  * Return value and type:
      * ErrorCode. OK
  * The main purpose of this method is to set the shape color
  * Specific use cases are as follows:
<code>
--Set the shape with id 1 to black
--The first parameter is the shape id
--The last three parameters are the colors to be changed, which are R, G, B (red, green, and blue)
MapMark:setShapeColor(1,0,0,0)
--Display in the chat box
Chat:sendSystemMsg("The shape with id 1 is set to black!")
</code>