Returns current color mode.
This method returns current color mode. The color mode defines how the series generates level colors.
It can be one of the following enumerated values:
- CM_SINGLE - colors are generated based on a single color (the first series color in the current theme)
- CM_MULTIPLE - colors are generated based on all series colors (all 5 series color in the current theme)
- CM_PALETTE - colors are generated based on rainbow colors
- CM_CUSTOM - colors are generated based on custom colors, that must have been previously added to m_arCustomSurfaceColors.
