The hex color #263e8d is a dark color. The web-safe version is Hex
#333399. A complementary color is
#D9C172. The grayscale version is
#505050. A 20% lighter version of the original color is
#5971C0, and Hex
#000B5A is the 20% darker color. If the color is saturated by 10%, you get
#223C93. If the color is desaturated by 10%, the color
#2A4087 is obtained.