RED function
Returns the red component of a color. The return value is an integer in the range of 0 to 255, inclusive. The input is an index of a color in the document's color table, an expression that resolves to a custom color (like RGB or HSL), or a reference to a cell that contains a color index or color result. The function returns 0 for invalid input.
Syntax
RED(expression)
Remarks
The return value is a number in the range 0 to 255, inclusive, or a cell reference that resolves to an index. If expression is invalid, this function returns 0 (black).
Example 1
RED(22)
Returns 51 if the document uses the default Microsoft Visio color palette, where dark gray is the color at index 22.
Example 2
RED(Char.Color)
Returns the value of the red component of the current font color.
Example 3
RED(RGB(10, 20, 30))
Returns 10.