CColorWell
Get ColorWell

ColorWell · contrast check

White or black text on #6366f1?

Tailwind indigo-500

Use black text. It gives 4.7:1, which passes AA, not AAA.

White text
4.47:1
passes AA for large text only (18pt+/14pt bold)
Black text
4.7:1
passes AA, not AAA

What the thresholds mean

LevelNeedsWhite textBlack text
AA, normal text4.5:1failpass
AA, large text (18pt+/14pt bold)3:1passpass
AAA, normal text7:1failfail

If you need the other one to pass

Same hue, moved along the lightness ramp until the ratio clears AA.

The colour itself

Shade ramp

#deebff #c7d5ff #abb8ff #8a94ff #6668fc #4e4ecb #37359c #221c70 #0f0547

Paste this into your config

// tailwind.config.js
colors: {
  brand: {
    100: "#deebff",
    200: "#c7d5ff",
    300: "#abb8ff",
    400: "#8a94ff",
    500: "#6668fc",
    600: "#4e4ecb",
    700: "#37359c",
    800: "#221c70",
    900: "#0f0547",
  },
}

Text colour to pair with the 500 shade (#6668fc): black, at 4.95:1. For #6366f1 itself it is black, at 4.7:1.

Your own colours, the same way

Paste any hex and get this page for it live — ratio, verdict, ramp. Export the whole palette to CSS variables, a Tailwind config or Figma tokens when you want it in the project rather than on the screen.

Open ColorWell

Other colours