The hex color #b7241c is a dark color. The web-safe version is Hex
#CC3333. A complementary color is
#48DBE3. The grayscale version is
#525252. A 20% lighter version of the original color is
#EA574F, and Hex
#840000 is the 20% darker color. If the color is saturated by 10%, you get
#C11F17. If the color is desaturated by 10%, the color
#AD2921 is obtained.