palettize create

The create command exports colormaps to one or more file formats for use in GIS applications, web mapping, and data visualization.

Usage

palettize create [PRESET_NAME] [OPTIONS]

Pass --format to export, --save to store the colormap, or both. A run with neither exits as a usage error.

Arguments

Argument	Description
PRESET_NAME	Preset name (e.g. viridis) or path to a saved colormap JSON file. Optional if --colors is provided.

Colormap Options

Option	Short	Default	Description
--colors	-c		List of input colors to create a colormap from.
--space	-s	oklch	Color space for interpolation.
--cut		0,1	Sub-segment of the colormap to use (e.g., 0.2,0.8).
--reverse	-r		Reverse the colormap before exporting.
--name			Name for the colormap, used in file naming and output.
--save			Write the colormap to this JSON path. Works without --format.

Output Options

Option	Short	Default	Description
--format	-f		Export format identifiers. Use multiple times or comma-separate. Required unless you only --save.
--output	-o	stdout	Output path pattern. Supports {name}, {format}, {ext} placeholders.
--steps	-n	7	Number of color steps. Minimum: 2. Also sets num_colors when that option is unset.
--precision			Decimal places for data values. Read by gdal and mapgl.

Data Domain and Scaling

Option	Short	Default	Description
--domain	-d	0,1	Data domain for scaling (e.g., 0,100 or -10,10).
--scale		linear	Scaling type: linear, power, sqrt, log, symlog.
--scale-exponent			Exponent for power scale. Required when --scale=power.
--scale-log-base		10	Log base for log or symlog scales.
--scale-symlog-linthresh			Linear threshold for symlog scale. Required when --scale=symlog.

--scale moves colors for gdal, mapgl, and for qgis / sld when they emit a gradient or ramp. Discrete QGIS ramps (exact, approximate) and discrete SLD maps (intervals, values) keep the colormap’s own stops. Other formats either ignore the scaler or record the scale name for the application to apply. palettize formats marks which formats use the domain and the scaler.

Format-Specific Options

Option	Short	Description
--option	-O	Pass format-specific options as key=value or exporter:key=value. Use multiple times.

Examples

Basic Export

# Export viridis to GDAL format
palettize create viridis --format gdal --output viridis.txt

# Export with custom data domain
palettize create viridis -f gdal -o viridis.txt --domain 0,255

Export Custom Colors

# Create a blue-white-red diverging colormap
palettize create --colors "blue,white,red" -f gdal -o bwr.txt --domain -100,100

Multiple Formats

Use the {name}, {format}, and {ext} placeholders in the output path:

palettize create viridis --format gdal,qgis,mapgl \
  --output "output/{name}_{format}.{ext}" \
  --domain 0,255 \
  --steps 11

This creates:

• output/viridis_gdal.txt
• output/viridis_qgis.xml
• output/viridis_mapgl.json

Control Number of Colors

# Generate 256 discrete colors
palettize create viridis -f gdal -o viridis.txt --steps 256

# Generate only 5 colors
palettize create viridis -f hex -n 5

Data Scaling

Linear (Default)

palettize create viridis -f gdal -o output.txt --domain 0,100 --scale linear

Square Root

palettize create viridis -f gdal -o output.txt --domain 0,100 --scale sqrt

Power

# Quadratic scaling (exponent=2)
palettize create viridis -f gdal -o output.txt --domain 0,100 --scale power --scale-exponent 2

Logarithmic

# Log base 10
palettize create viridis -f gdal -o output.txt --domain 1,1000 --scale log

# Log base 2
palettize create viridis -f gdal -o output.txt --domain 1,1024 --scale log --scale-log-base 2

Symmetric Log (for data spanning zero)

palettize create --colors "blue,white,red" -f gdal -o output.txt \
  --domain -100,100 --scale symlog --scale-symlog-linthresh 1

Format-Specific Options

Use -O or --option to pass options to specific exporters:

# Set Observable Plot scale type
palettize create RdBu -f observable -o plot.json \
  --domain -5,10 -O type=diverging -O pivot=0

# Target a specific exporter
palettize create viridis -f gdal,qgis \
  -O gdal:nodata_value=0 -O qgis:ramp_type=exact

Print to Standard Output

Omit --output to print the result:

# Print hex colors
palettize create viridis -f hex -n 5

Output:

#440154
#3b528b
#21918d
#5cc863
#fde725

Verbose Output

palettize -v create viridis -f gdal -o viridis.txt --domain 0,255

Output:

Exporting to gdal...
Wrote viridis.txt
Export complete.

Save without Exporting

palettize create viridis --cut 0.2,0.8 --reverse --save my-map.json

Available Formats

Run palettize formats for the live list, including each format’s options:

Identifier	Description
gdal	GDAL Color Relief Text
qgis	QGIS Color Ramp XML
sld	OGC SLD XML
titiler	TiTiler Colormap URL Parameter
mapgl	MapLibre GL JS Expression
observable	Observable Plot Scale
gee	Google Earth Engine Snippet
css	CSS Custom Properties
svg	SVG Gradient
gimp	GIMP Palette
json	JSON
hex	Plaintext Hexadecimal
rgba	Plaintext RGBA
hsl	Plaintext HSL

See Export Formats for detailed documentation of each format.