Design Bible

Color Theory

Interactive tools and reference for applying color theory in web design.

60-30-10 Color Rule Visualizer

The classic proportion rule: 60% dominant (backgrounds/surfaces), 30% secondary (nav, cards, sections), 10% accent (CTAs, links, highlights). Click the color blocks to pick new colors.

60% Dominant

Backgrounds & large surfaces

#F5ECD7

30% Secondary

Cards, nav, section fills

#7A8C5C

10% Accent

CTAs, links, highlights

#C06C45

Café PreviewReserve

Latte

Single origin

$5.00

Espresso

Single origin

$5.00

Matcha

Single origin

$5.00

Color Psychology

How each color family communicates with viewers and how to apply it in web design.

Red

UrgencyPassionDangerAppetite

CTAs, sale/promo alerts, food imagery

Orange

EnergyWarmthFriendlinessAffordability

Casual food brands, sports, youth brands

Yellow

OptimismClarityCautionAttention

Highlights, warnings, café/bakery brands

Green

HealthNatureGrowthPermission

Organic brands, finance, sustainability

Blue

TrustProfessionalismCalmTechnology

SaaS, banking, healthcare, formal services

Purple

LuxuryCreativitySpiritualityMystery

Premium beauty, arts, wellness, wine

Pink

RomanceFemininityPlayfulnessSweetness

Beauty, desserts, fashion, children's

Brown

EarthinessStabilityCraftTradition

Coffee, chocolate, rustic food brands

Black

SophisticationAuthorityPowerLuxury

Premium brands, fashion, fine dining

White

CleanlinessSpaceSimplicityPurity

Healthcare, minimalist brands, tech

WCAG Contrast Checker

Check if your text/background color combinations meet accessibility standards. AA = minimum legal standard in most countries.

Text / Foreground

#1A1A1E

Background

#E8E0D2

Heading Text

Body copy — this is how your text will look on this background. The quick brown fox jumps over the lazy dog.

Button Label

Contrast Ratio

13.24:1

Excellent — AAA compliant

WCAG AA (4.5:1 normal / 3:1 large)

Normal Text
Large Text

WCAG AAA (7:1 normal / 4.5:1 large)

Normal Text
Large Text
Tip: WCAG AA is the minimum accessibility standard required by law in many countries. Always test body text (below 18px) at 4.5:1 minimum. Large text (18px+) requires only 3:1.

HSL vs HEX vs RGB

HEX (#FF5733)

Most common format for design handoffs and CSS. Concise and universally supported — but not human-readable. Use HEX in final production code and design files.

RGB (192, 108, 69)

Separates a color into Red, Green, Blue (0–255 each). Useful for opacity control with rgba(). Slightly more readable than HEX but still not intuitive.

HSL (22, 45%, 51%)

Most human-readable format. Hue (0–360°), Saturation (0–100%), Lightness (0–100%). Best for building design systems — you can adjust lightness systematically to create tints and shades.

Use HSL for CSS variables and design systems. Use HEX for design tools and handoffs.

Dark Mode Palette Adaptation

Backgrounds

Replace light neutrals with very dark values of your primary hue (lightness 6–12%). Never use pure black — a dark-tinted background feels more immersive than #000000.

Text

Replace dark text with a warm off-white (lightness 85–92%). Pure white text on dark backgrounds is too harsh and causes eye fatigue.

Primary & Secondary

Shift the primary color's lightness up by 10–15% to compensate for reduced perceived saturation on dark backgrounds.

Accents

Increase lightness significantly — dark-mode accents must be brighter to have impact.

Flipping a light palette to dark mode is not simply 'inverting colors.' A naive inversion creates harsh, unrealistic results.

5-Step Palette Building Process

Step 1 — Define the emotion

What should the visitor feel within 3 seconds? Write one sentence: 'This café should feel warm, honest, and handcrafted.' That sentence is your filter for every decision.

Step 2 — Choose your primary hue

Pick one color that captures the core emotion. Keep it at medium saturation (40–60%) and medium lightness (40–55%) for versatility.

Step 3 — Derive your background

Take your primary hue, reduce saturation to 10–20%, and raise lightness to 90–97%. This creates a tinted neutral background.

Step 4 — Choose your secondary color

Use an analogous color (30° away on the color wheel) or a neutral in the same temperature family.

Step 5 — Set text and accent

Text: dark version of your primary (lightness 10–20%). Accent: complementary or saturated version of primary. Test WCAG AA: 4.5:1 minimum.

Always document each color with its role and HSL/HEX values — a palette without documentation is a liability.