The hex color #ddff99 is a light color. The web-safe version is Hex
#CCFF99. A complementary color is
#220066. The grayscale version is
#D2D2D2. A 20% lighter version of the original color is
#FFFFCC, and Hex
#AACC66 is the 20% darker color. If the color is saturated by 10%, you get
#DEFF93. If the color is desaturated by 10%, the color
#DCFA9F is obtained.