Presets and palettes

Presets, the seed color generator and the palette generator each fill every color field at once. Reach for them to start a theme in one click, then refine single surfaces under Colors.

Quick start

1. Open the editor at themes.extension.dev/chromium and click Presets on the dock.
2. Pick Ocean Blue from the preset list. Every color field and the window mock take the preset's values.
3. Type #4285f4 under Start from a color and click Dark theme. The colors are rebuilt from that seed and your images stay.

How it works

Presets replace colors. Picking a preset replaces your current colors with the preset's values, and you fine-tune afterward. Each preset carries tags such as Dark, Light, High contrast or Playful. Aurora is the one preset that also brings images: a northern-lights wallpaper with a deep night frame.

Randomize colors. The Randomize button draws new frame, toolbar and New Tab colors at random. It keeps your images, the attribution toggle, the NTP alignment and repeat, the logo setting, tints and any imported keys the editor does not edit. Each text color is nudged until it passes 4.5:1 against its surface.

Start from a color. Type a seed hex in the field, which starts at #4285f4, then click Light theme or Dark theme. The editor builds the theme Chrome's own Customize Chrome panel would build from that seed, using Google's HCT color library. Colors are replaced and images are kept.

Generate palette. The palette generator takes a base color, a palette type and a theme mode. Monochromatic stays on one hue, Complementary pairs the hue with its opposite, and Analogous uses the two neighboring hues. Dark or Light sets which surfaces go deep and which stay bright. Every text color passes through the AA contrast check before it lands.

Undo covers all of them. A preset, a randomize, a seed or a palette is one history step, so Cmd+Z or Ctrl+Z restores the theme you had.

Reference

Preset	Tags
Default	Dark
Material Dark	Dark
Light & Clean	Light
Ocean Blue	Dark
Forest Green	Dark
Sunset Orange	Playful
High Contrast	High contrast, Dark
Midnight Purple	Dark
Aurora	Dark, Playful, with a wallpaper

Control	Input	Keeps
Preset	One of nine	Nothing, colors are replaced
Randomize colors	None	Images, alignment, repeat, logo, tints, imported keys
Start from a color	Seed hex, Light or Dark	Images
Generate palette	Base hex, type, mode	Nothing, colors are replaced

Palette type	Hues used
Monochromatic	The base hue
Complementary	The base hue and the hue 180 degrees away
Analogous	The base hue and the hues 30 degrees either side

When it fails

• "Enter a hex color such as #3b82f6 or #38f." The base color is not a three or six digit hex. Fix the value and generate again.
• Light theme and Dark theme are disabled. The seed field holds no readable hex. Clear it and the field returns to #4285f4.
• A preset wiped colors you wanted. Press Cmd+Z or Ctrl+Z. The preset was one history step.
• "Could not generate the theme. Try again." The seed build failed in this browser. Try the same seed again, or pick a preset.

Next

• Colors
• Images and tints
• The editor
• Templates