`TfpgColorWheel`
pt		HSFromPoint
pt		DrawCursor
pt		SetMarginWidth
pt		SetCursorSize
pt		SetValueBar
pt		SetWhiteAreaPercent
pt		SetBackgroundColor
pt		Notification
pt		DrawWidth
pt		DrawHeight
pt		Change
pt		HandlePaint
pt		HandleLMouseDown
pt		HandleMouseMove
pt		HandleLMouseUp
		Create
		Destroy
		SetSelectedColor