HEX, RGB and HSL: which color format to use
The picker gives every color in three formats. Here is what each one means and when to reach for hex, RGB, or HSL in real work.
What the three formats describe
All three formats point to the same color, they just write it differently. Hex is a six digit code like #3b82f6, packing the red, green, and blue channels into pairs of base sixteen digits. RGB spells those same channels out as three numbers from 0 to 255, so #3b82f6 is rgb(59, 130, 246). HSL takes a different angle, describing the color as a hue on a 0 to 360 degree wheel plus a saturation and a lightness percentage, which for that blue is hsl(217, 91%, 60%). The picker computes all three from the one pixel you click.
When hex is the right pick
Hex is the default currency of the web and most design tools. It is compact, unambiguous, and drops straight into CSS, HTML, and nearly every graphics program. Because it maps exactly to the stored byte values with no rounding, it is the safest format to copy when you need a color to match perfectly across tools. When someone asks for a brand color, they almost always want the hex.
When RGB earns its place
RGB shines when you need to work with the channels as numbers rather than a code. It is the natural format for adding an alpha channel as rgba, for feeding colors into a script or spreadsheet, and for reasoning about how much red, green, or blue a pixel holds. Since the picker already shows RGB as three plain integers, it saves you converting a hex code by hand when a language or API expects separate values.
When HSL makes editing easier
HSL is built for adjusting a color rather than just recording it. Because hue, saturation, and lightness are separated, you can nudge one without disturbing the others: keep the hue and drop the lightness for a darker shade, or hold lightness and cut saturation for a muted version. That makes HSL the friendliest format for building tints, shades, and consistent palettes around a color you sampled from an image.