HEX (Hexadecimal)
A # followed by 6 hex digits — each pair represents red, green, and blue channels (00–FF).
#FF5733 → Red=255, Green=87, Blue=51
#000000 → Black
#FFFFFF → White
#3B82F6 → Blue (Tailwind blue-500)
Use when: CSS properties, HTML attributes, design tools (Figma, Sketch)
RGB (Red, Green, Blue)
Three integers from 0–255 for each color channel. RGBA adds a 0–1 opacity value.
rgb(255, 87, 51) → orange-red
rgba(255, 87, 51, 0.5) → 50% transparent orange-red
Use when: CSS, dynamic color calculation in JavaScript, image processing
HSL (Hue, Saturation, Lightness)
Hue (0–360°), saturation (0–100%), lightness (0–100%) — the most intuitive format for humans.
hsl(14, 100%, 60%) → orange-red
hsl(0, 0%, 0%) → black
hsl(0, 0%, 100%) → white
Use when: Generating color variants (hover states), building color scales, design system tokens
How to Convert Colors Online
Use tool.tl's color converter:
- Go to tool.tl/color-converter
- Enter a color value in any format (HEX, RGB, or HSL)
- All other formats update in real time with a live color preview
- Click to copy any format instantly
HEX ↔ RGB Conversion in Code
# Python
hex_color = '#FF5733'
r = int(hex_color[1:3], 16) # 255
g = int(hex_color[3:5], 16) # 87
b = int(hex_color[5:7], 16) # 51
// JavaScript — RGB to HEX
const toHex = (r, g, b) =>
'#' + [r, g, b].map(v => v.toString(16).padStart(2, '0')).join('').toUpperCase();
toHex(255, 87, 51); // '#FF5733'
Why HSL Is Best for Color Scales
HSL makes it trivial to generate tints and shades — just adjust lightness while keeping hue and saturation constant:
hsl(217, 91%, 90%) → blue-100 (lightest)
hsl(217, 91%, 60%) → blue-400
hsl(217, 91%, 50%) → blue-500 (base)
hsl(217, 91%, 35%) → blue-700
hsl(217, 91%, 20%) → blue-900 (darkest)
Frequently Asked Questions
When should I use HEX vs RGB vs HSL?
They're equivalent in what they can express. HEX is most concise for static values in CSS. RGB/RGBA is convenient when you need transparency. HSL is best when you need to programmatically adjust colors — lightness changes are predictable and intuitive.
Is HEX case-sensitive?
No — #FF5733 and #ff5733 produce identical colors. Pick one style and be consistent within a project.
Yes — tool.tl's color converter is completely free, real-time conversion, no account needed.