The hex color #21dbb9 is a light color. The web-safe version is Hex
#33CCCC. A complementary color is
#DE2446. The grayscale version is
#929292. A 20% lighter version of the original color is
#54FFEC, and Hex
#00A886 is the 20% darker color. If the color is saturated by 10%, you get
#16E2BD. If the color is desaturated by 10%, the color
#2CD4B5 is obtained.