Lighten & darken a color

Lighten or darken a color by a specific amount, essentially change its brightness. You know when you want to tweak a color in an image, for example when the background color is a bit too light for your liking and you want the same color but a bit darker so you dont burn your retina?

The light and dark subcommands help you do exactly that using a simple -f (or --factor) flag.

# Lighten a color by 30% (default factor with no flag)
gowall color light "#FF5733"
gowall color light "#FF5733" -f 0.45

# Darken a color by 30% (default factor with no flag)
gowall color dark "#FF5733"
gowall color dark "#FF5733" -f 0.2

You can pass colors in any format that gowall understands (for example hex, rgb, hsl, lab) as shown in here and it will output a lightened or darkened version.

gowall color dark "rgb(255,255,255)" -f 0.3

Usage & Options

➤ Factor

The --factor (or -f) flag controls how much to lighten or darken the color. You can use a negative factor

• Range: -1.0 to 1.0 For example if you use the gowall color dark command a positive factor darkens the color and a negative factor lightens the color. The opposite is true for the gowall color light command.
• Default: 0.3 (i.e. 30% lighter or darker)

# 30% lighter (implicit default)
gowall color light "#FF5733"

# 60% lighter
gowall color light "#FF5733" -f 0.6

# 20% darker
gowall color dark "#FF5733" -f 0.2