The hex color #21826c is a dark color. The web-safe version is Hex
#339966. A complementary color is
#DE7D93. The grayscale version is
#5A5A5A. A 20% lighter version of the original color is
#54B59F, and Hex
#004F39 is the 20% darker color. If the color is saturated by 10%, you get
#1B866E. If the color is desaturated by 10%, the color
#277E6A is obtained.