The hex color #99e90f is a light color. The web-safe version is Hex
#99FF00. A complementary color is
#6616F0. The grayscale version is
#868686. A 20% lighter version of the original color is
#CCFF42, and Hex
#66B600 is the 20% darker color. If the color is saturated by 10%, you get
#9BF303. If the color is desaturated by 10%, the color
#97DF1B is obtained.