The hex color #f99f10 is a light color. The web-safe version is Hex
#FF9900. A complementary color is
#0660EF. The grayscale version is
#8D8D8D. A 20% lighter version of the original color is
#FFD243, and Hex
#C66C00 is the 20% darker color. If the color is saturated by 10%, you get
#FFA103. If the color is desaturated by 10%, the color
#EE9D1D is obtained.