void gtk_hsv_to_rgb (gdouble h, gdouble s, gdouble v,
gdouble *r, gdouble *g, gdouble *b);
void gtk_rgb_to_hsv (gdouble r, gdouble g, gdouble b,
void gtk_hsv_to_rgb (gdouble h, gdouble s, gdouble v,
gdouble *r, gdouble *g, gdouble *b);
void gtk_rgb_to_hsv (gdouble r, gdouble g, gdouble b,