HEX, RGB and HSL: three descriptions of one color
A design editor may request HEX while another file uses RGB or HSL. Conversion helps carry the same color across those formats; it does not automatically improve it or guarantee a screen-to-print match.
HEX is compact RGB notation
In six-digit HEX, each pair describes a red, green or blue channel from 0 to 255. The three-digit shorthand repeats each digit rather than inserting zeros.
This converter uses opaque sRGB colors and accepts three- or six-digit HEX. CSS can add alpha in eight-digit notation, but that transparency form is outside this tool’s current scope.
References: W3C CSS Color 4 — Hexadecimal RGB and HSL
HSL changes how you describe the color
Hue, saturation and lightness are useful when thinking about a less saturated or lighter version rather than adjusting three RGB channels without a clear direction.
HSL lightness is not a uniform measure of perceived brightness. Equal percentages for different hues do not establish equal apparent lightness or suitability for text.
References: W3C CSS Color 4 — Hexadecimal RGB and HSL
Conversion does not validate every design decision
Check a text color against its actual background when readability matters. A valid code or attractive swatch alone does not establish sufficient contrast.
Keep the original reference when moving to print or another color space. This is not screen calibration or CMYK conversion, and rewriting HSL before returning to eight-bit RGB can introduce small rounding differences.
Example: expand a short code without changing the color
#369 expands to #336699. The pairs 33, 66 and 99 give RGB values 51, 102 and 153, not 3, 6 and 9. The same color has HSL values of 210 degrees, 50% saturation and 40% lightness.
These are three descriptions, not three shades. Changing lightness to 60% selects another color, and adding an alpha channel introduces a separate transparency decision absent from the opaque original.