Specifies the color of transparency.
__property int TransparentColor;
Description
Use TransparentColor to specify the color of transparency. Transparent color is a dedicated color in your palette that is never used as a real color on your transparent surface. The transparent pixels are never copied when you are copying a transparent surface onto another surface. You must set Transparent to true to enable transparency. The default value for TransparentColor is 0.
Once you have created a surface, you can't change the transparent color. You need to use RecreateOffScreen to change the TransparentColor.
Notes
Note that TransparentColor is not a TColor. Instead, it's an integer. You should only use the lower 8 bits of that value to index a color in your palette.