Modify alpha, hue, saturation and value (HSV) of a color
colorAdjust(color, alpha = NULL, hue = 0, sat = 0, val = 0)
Input color. Any format that grDevices::col2rgb() recognizes
Numeric: Scale alpha by this amount. Future: replace with absolute setting
Float: How much hue to add to color
Float: How much saturation to add to color
Float: How much to increase value of color
by
Adjusted color