A design specification may list a colour in HEX while an editor asks for RGB or HSL. The colour can be represented in all three forms, but the field ranges are different.
Open HEX RGB HSL Color Converter and select the representation you are entering. The tool returns the corresponding opaque colour values and a visual swatch.
Red is a useful check
HEX #FF0000 corresponds to RGB 255, 0, 0. In HSL, it is hue 0, saturation 100% and lightness 50%. Entering those HSL values should produce the same red swatch.
RGB channels range from 0 to 255. HSL uses a hue angle and percentage values for saturation and lightness. Do not paste the three RGB numbers into HSL fields as though the scales were interchangeable.
Short HEX values can be expanded by the tool, but a malformed HEX string produces an error. Use the colour input mode that matches the source instead of deleting symbols until the form accepts something.
A swatch is not a contrast judgement
This converter does not calculate accessible text contrast. A colour that looks attractive in isolation may still be difficult to read against a chosen background. Evaluate the foreground and background together with an appropriate contrast tool.
Alpha transparency is outside this opaque conversion. The result does not describe how a partly transparent layer will look after blending with another colour.
Small rounding differences can occur when moving between HSL percentages and integer RGB channels. Keep the final HEX or RGB value as the agreed design reference when exact reproduction matters.
For a website palette, save the colour value with its role, such as heading or button. Converting its notation does not decide whether it fits every component of the design.