The hex color #1f99f3 is a dark color. The web-safe version is Hex
#3399FF. A complementary color is
#E0660C. The grayscale version is
#8E8E8E. A 20% lighter version of the original color is
#52CCFF, and Hex
#0066C0 is the 20% darker color. If the color is saturated by 10%, you get
#149AFD. If the color is desaturated by 10%, the color
#2A98E9 is obtained.