Decimal vs hexadecimal color codes: RGB(255,0,0) vs #FF0000 explained
Colors in CSS and design tools use two numeric formats for the same RGB data: decimal (rgb(255, 0, 0)) and hexadecimal (#FF0000). Decimal values range 0-255 per channel. Hex uses two hex digits (00-FF) per channel, concatenated. Both represent exactly the same color. The choice is about readability and tool compatibility.
How this is calculated
Hex is more compact (7 characters vs 15+), aligns with how colors are stored in memory (one byte per channel = two hex digits), and is the traditional format in web development and design tools like Figma. Decimal RGB is more intuitive for adjusting colors programmatically because you can do math on the values without converting from hex. Modern CSS also supports functional notations like hsl() and oklch() that are more intuitive for designers. Converting between hex and decimal is straightforward: each pair of hex digits represents a byte value from 0-255.
Verdict
Use hex (#FF0000) for static color values in CSS and design handoff. Use decimal rgb() when generating colors dynamically in JavaScript. Use hsl() or oklch() when designing color systems and need to reason about lightness and saturation. The formats are interchangeable, so pick the one that matches your workflow.