Color.HSV
From Xojo Documentation
Shared Method
Returns a Color from hue, saturation and value. These values are represented by Doubles between 0 and 1.
Notes
The alpha parameter provides the ability to control transparency and is an integer between 0 and 255. Zero is completely opaque and 255 is transparent. If omitted, the default is 0 (no transparency).
Sample Code
Set a color using hue, saturation and value: