NoNoiseTools

Developer tools

Color Converter

Enter a HEX, RGB or HSL colour value to see equivalent CSS colour formats and a preview. This tool focuses on opaque colour values.

Convert colour

Enter a HEX, RGB or HSL value, then convert it to the other supported CSS colour formats.

Supports opaque HEX, RGB and HSL values. Alpha and CSS colour names are out of scope.

Input format

Auto detects supported formats or enforces one format.

Formatting

Privacy notes

Colour values are converted in this browser tab. NoNoiseTools does not need to upload pasted colour text for this tool.

Colour values are usually not sensitive, but avoid pasting CSS snippets that include secrets, tokens or private project context.

How this colour converter works

The converter parses one supported colour value, converts it through RGB, then writes equivalent HEX, RGB and HSL strings. It does not upload the value or fetch external colour data.

Supported formats

This version supports short and long HEX, RGB channel values from 0 to 255, and HSL values with percentage saturation and lightness. Alpha values, CSS colour names and palette generation are outside this first version.

Preview and copy output

After conversion, the preview swatch uses the generated HEX colour. Each output format has its own copy button so you can paste the exact value into CSS, design notes or documentation.

Privacy notes

Colour values are converted in the browser. NoNoiseTools does not need to upload pasted colour text to a server for this tool.

Colour values are usually not sensitive, but avoid pasting CSS snippets that include secrets, tokens, private project names or unreleased design-system details unless you trust this device.

What this tool does not include

It does not sample images, check accessibility contrast, name colours, generate palettes, support transparency or manage design tokens.

Key terms and assumptionsShort notes about supported colour formats, alpha exclusions, rounding and browser-side conversion.
Opaque colours only
Alpha, RGBA, HSLA and 4/8-digit HEX values are outside this version.
Narrow CSS syntax
The parser accepts common numeric HEX, RGB and HSL forms, not CSS colour names or every modern CSS syntax.
Rounded HSL output
Converted HSL values are rounded to whole-number hue and percentages for stable copy output.
Browser conversion
Colour parsing and conversion happen in the browser tab.
Preview only
The swatch previews the converted colour but does not test accessibility contrast.

Related tools

FAQs

Which colour formats are supported?

This version supports opaque HEX, RGB and HSL values.

Can I convert short HEX values?

Yes. Short values such as #369 expand to full HEX.

Does this support transparency?

Not in this version. Alpha formats such as HEXA, RGBA and HSLA are rejected.

Does it support CSS colour names?

Not in this version. The first version stays focused on numeric colour formats.

Is my colour value uploaded?

No. The conversion happens in your browser.

Why did my RGB input fail?

RGB channels should be whole numbers from 0 to 255.

Does this check accessibility contrast?

Not in this version. A future colour contrast checker should be a separate scoped tool.