---
name: "r.what.color"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "8.4.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/r.what.color"
---

# r.what.color(1grass)

Queries colors for a raster map layer.

## NAME

**r.what.color**  - Queries colors for a raster map layer.

## KEYWORDS

raster, querying, color table

## SYNOPSIS

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

### 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**=*string* **\[required\]**

  Name of existing raster map to query colors

- **value**=*float\[,float*,...\]

  Values to query colors for

- **format**=*string*

  Output format (printf-style)\
   Default: *%d:%d:%d*

## DESCRIPTION

*r.what.color* outputs the color associated with user-specified category values in a raster input map.

Values may be specified either using the **values=** option, or by specifying the **-i** flag and passing the values on `stdin`, one per line.

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).

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
*: *
```

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
```

Common formats:\

- •

  Tcl/Tk: `format="#%02x%02x%02x"`

- •

  WxPython: `format=’"#%02x%02x%02x"’`  or  `format=’"(%d,%d,%d)"’`

## SEE ALSO

*r.what*

## AUTHOR

Glynn Clements

## SOURCE CODE

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

Accessed: Monday Feb 24 17:50:58 2025

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