HEX vs RGB vs HSL: Which Color Format Should You Use?

Published April 2025 · 6 min read

Every color on a screen can be written in several different formats, and design tools, code editors, and specifications rarely agree on which one to show you. The good news: they all describe exactly the same colors — the difference is which properties are easiest to read and adjust for a given task.

HEX: compact and everywhere

HEX codes look like #2d6a4f — a hash symbol followed by six hexadecimal digits. The first two digits encode red, the next two green, the last two blue, each ranging from 00 to ff (0–255 in decimal). HEX is the default format in most design tools (Figma, Photoshop, Sketch) and is extremely common in CSS and HTML because it's compact and easy to copy-paste as a single unit.

Best for: quickly copying a color between design tools and code, and anywhere you need a short, unambiguous color reference.

RGB: explicit color channels

RGB writes the same information as three separate numbers: rgb(45, 106, 79). This is the same color as the HEX example above, just spelled out. Because each channel is a separate number, RGB is genuinely easier to work with in code when you need to manipulate red, green, or blue independently — for example, gradually increasing the blue channel in an animation.

Best for: programmatic color manipulation, and situations where you need transparency via rgba(), which adds a fourth alpha value (e.g. rgba(45, 106, 79, 0.5) for 50% opacity).

HSL: the format that matches how humans think about color

HSL stands for Hue, Saturation, Lightness — hsl(152, 41%, 30%) for that same green. This format maps much more closely to how people naturally describe color:

• Hue (0–360°) — the base color itself, positioned around a color wheel (0° is red, 120° is green, 240° is blue).
• Saturation (0–100%) — how vivid or muted the color is; 0% is grey, 100% is fully saturated.
• Lightness (0–100%) — how light or dark the color is; 0% is black, 100% is white, 50% is the "pure" version of the hue.

Best for: building color palettes and variations. Want a lighter or darker version of your brand color while keeping the exact same hue? Just change the lightness value and leave hue and saturation untouched — something that's much harder to do by eye in HEX or RGB.

Quick reference table

They're always interchangeable

None of these formats carry any extra information over the others — a color converter can move between them instantly and losslessly, since they're just different ways of writing the same red/green/blue values. Choosing a format is really about which one is easiest for the specific task in front of you, not about which one is "correct."