Use HSL color model with GMT

Is there a way to use the HSL color model with GMT? I know it uses HSV but this is a problem for me when trying to illuminate a categorical CPT as it changes the color and not just lightens or darkens the color as HSL would.

From the docs:

If the intensity is non-zero, the color is either lightened or darkened depending on the illumination. The color is first converted to HSV (if necessary) and then darkened by moving (sv ) toward (COLOR_HSV_MIN_S, COLOR_HSV_MIN_V) if the intensity is negative, or lightened by sliding (sv ) toward (COLOR_HSV_MAX_S, COLOR_HSV_MAX_V) if the illumination is positive.

I don’t think there is a HSL model in GMT.