The hex color #d7dde9 is a light color. The web-safe version is Hex
#CCCCFF. A complementary color is
#282216. The grayscale version is
#DFDFDF. A 20% lighter version of the original color is
#FFFFFF, and Hex
#A4AAB6 is the 20% darker color. If the color is saturated by 10%, you get
#D6DDEA. If the color is desaturated by 10%, the color
#D8DDE8 is obtained.