Keep one color across formats
HEX and RGB describe red, green and blue channels. HSL describes hue, saturation and lightness; HSV uses value instead of lightness. The fields show the same color, with rounding only in the displayed numbers. To use a color from an image, sample its pixel.
A worked example
The HEX value #0B7285 is rgb(11, 114, 133). Sending it to the palette tool keeps that exact seed color. To find companion colors for your seed, make a palette.
Before you use the result
These are sRGB colors. Printed color depends on ink, paper and the printing process. Opacity blends with the background; the solid preview sits on white.