The hex color #b6213c is a dark color. The web-safe version is Hex
#CC3333. A complementary color is
#49DEC3. The grayscale version is
#5C5C5C. A 20% lighter version of the original color is
#E9546F, and Hex
#830009 is the 20% darker color. If the color is saturated by 10%, you get
#BF1B39. If the color is desaturated by 10%, the color
#AD273F is obtained.