The hex color #2b3f4e is a dark color. The web-safe version is Hex
#333366. A complementary color is
#D4C0B1. The grayscale version is
#3D3D3D. A 20% lighter version of the original color is
#5E7281, and Hex
#000C1B is the 20% darker color. If the color is saturated by 10%, you get
#293F50. If the color is desaturated by 10%, the color
#2D3F4C is obtained.