r.what.color(1grass)

✨ r.what.color — bestie edition ✨

okay so. quick vibe check: this is r.what.color, part of the GRASS User's Manual, and it's giving tiny tool, huge utility. it asks a raster map "hey what color is this value" and the map tells you. that's it. that's the whole thing. and yet 💅

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🌸 NAME 🌸

r.what.color — Queries colors for a raster map layer.

🏷️ KEYWORDS 🏷️

raster, querying, color table

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👑 SYNOPSIS 👑

r.what.color
r.what.color --help
r.what.color [-i] input=name  [value=float[,float,...]]
[format=string]  color_format=name  [--help]  [--verbose]  [--quiet]
[--ui]

🎀 Flags 🎀

• -i — Read values from stdin
• --help — Print usage summary
• --verbose — Verbose module output
• --quiet — Quiet module output
• --ui — Force launching GUI dialog

🦋 Parameters 🦋

• input=name [required] — Name of input raster map
• value=float[,float,...] — Values to query colors for
• format=string — Output format ('plain', 'json', or printf-style string). Output format printf-style is deprecated, use 'color_format' option instead. Default: %d:%d:%d
• color_format=name [required] — Color format. Color format for output values. Applies only when format is set to 'plain' or 'json'. Options: rgb, hex, hsv, triplet. Default: hex
  • rgb: output color in RGB format
  • hex: output color in HEX format
  • hsv: output color in HSV format (experimental)
  • triplet: output color in colon-separated RGB format

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💖 DESCRIPTION 💖

no cap, here's the tea: r.what.color outputs the color associated with user-specified category values in a raster input map. like, you hand it a number, it hands you back the color. iconic behavior fr fr.

You can give it values two ways: either with the values= option, or by specifying the -i flag and passing the values on stdin, one per line. your call bestie 🫶

For each value which is specified, a line of output will be generated consisting of the category value followed by the color, e.g.:

r.what.color input=elevation.dem value=1500
1500: 223:127:31

If the input map is an integer (CELL) map, the category will be written as an integer (no decimal point), otherwise it will be written in floating point format (printf("%.15g") format). the way it just knows 🧚

If the lookup fails for a value, the color will be output as an asterisk, e.g.:

r.what.color input=elevation.dem value=9999
9999: *

If a value cannot be parsed, both the value and the color will be output as an asterisk, e.g.:

r.what.color input=elevation.dem value=bogus
*: *

mystery value? mystery color. * to *. we love a symmetrical fail 😭

The format can be changed using the format= option. The value should be a printf()-style format string containing three conversion specifiers for the red, green and blue values respectively, e.g.:

r.what.color input=elevation.dem value=1500 format='%02x:%02x:%02x'
1500: df:7f:1f

If your system supports the %m$ syntax, you can change the ordering of the components, e.g.:

r.what.color input=elevation.dem value=1500 format='%3$02x:%2$02x:%1$02x'
1500: 1f:7f:df

reorder the parts?? main character energy tbh. BGR girlies rise up 💅

Common formats:

• Tcl/Tk: format="#%02x%02x%02x"
• WxPython: format='"#%02x%02x%02x"' or format='"(%d,%d,%d)"'

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👀 SEE ALSO 👀

r.what

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⭐ AUTHOR ⭐

Glynn Clements

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📜 SOURCE CODE 📜

Available at: r.what.color source code (history)

Latest change: Thursday Oct 02 14:39:13 2025 in commit: 1850489bf42c72d8dcfe2e4db1738441b4a7dc43

Main index | Raster index | Topics index | Keywords index | Graphical index | Full index

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okay that's the whole page, you ate that 🍓 now go query some colors and slay responsibly. this was GRASS 8.5.0 — yes that's the version — dated Thursday Oct 02 14:39:13 2025, copyright sits with © 2003-2026 GRASS Development Team (they've been holding it down for a minute, periodt 👑). byeee 💖