Colormap

Colormap is a Java package for creating and using colormaps. It includes many "reference" colormaps, including those from Matplotlib , Tableau and other sources (see credits).

Overview

• The main access to the colormaps is through net.mahdilamb.colormap.Colormaps. This includes a lot of wrapper classes and the ability to list the reference colormaps Colormaps.named().
• The wrapper classes include a reversed colormap (Colormaps.reversedColormap()), as well as a "fluid" colormap Colormaps.fluidColormap(). A fluid colormap is not, unlike the reference colormaps, limited to the range 0-1. Instead, a fluid colormap can autoscale, or be clamped between a min and max value (see net.mahdilamb.colormap.FluidColormap for more information). Fluid colormaps can also have the backing colormap changed.

Using reference colormaps

Reference colormaps can either be accessed through Colormaps.get(String), which can take a String such as "sequential.viridis", "viridis" or "sequential.viridis.reversed". Alternatively, they can be accessed using a class path embedded in the Colormaps class e.g. Colormaps.Sequential.Viridis() (and then, for exampled made fluid Colormaps.fluidColormap(Colormaps.Sequential.Viridis())).

Creating colormaps

Colormaps can be created in two ways either using a builder Colormaps.buildSequential() and Colormaps.buildQualitative(), or by extending net.mahdilamb.colormap.SequentialColormap and net.mahdilamb.colormap.QualitativeColormap. Reference colormaps are created by the latter approach.

Fluid colormaps example

As the fluid colormaps are autoranging, they fire an even when the color is changed. The below example shows how this might be done using a lambda expression. The original value is 0, but this changes when a new color is requested from the colormap, and the range is changed, and a new event is triggered.

import net.mahdilamb.colormap.Colormaps;
import net.mahdilamb.colormap.FluidColormap;

public class Test {
    public static void main(final String[] args) {
        final FluidColormap viridis = Colormaps.fluidColormap(Colormaps.get("Viridis"));
        viridis.get(0f, color -> {
            System.out.println(color);
        });

        viridis.get(-1);
    }
}

Color

The colormap package includes a Colors utility class net.mahdilamb.colormap.Colors. It holds constants for the colors specified in CSS4, AWT and Tableau.

Developer note

It is possible to also include the xkcd colors. The addition of the colors is done automatically from text files in src\test\java\net\mahdilamb\colormap\reflect\InsertColors.java. Uncomment the line referring to the xkcd file parsing and add an extra method in the Color class.

public static Color getXKCD(String name) {
    return get(ColorType.XKCD, name);
}

Maven

The package can be imported from maven.

Reference colormaps

Category	ColorMap	Sample	Source
Cyclic	Edge		Paraview
Cyclic	HSV
Cyclic	IceFire		Paraview
Cyclic	MRYBM		CET
Cyclic	MYGBM		CET
Cyclic	Phase		CMOcean
Cyclic	Twilight		matplotlib
Cyclic	TwilightShifted		matplotlib
Diverging	ArmyRose		CARTO
Diverging	Balance		CMOcean
Diverging	BentCoolWarm		Kenneth Moreland
Diverging	BrBG		ColorBrewer
Diverging	Curl		CMOcean
Diverging	Delta		CMOcean
Diverging	Diff		CMOcean
Diverging	Earth		CARTO
Diverging	Fall		CARTO
Diverging	Geyser		CARTO
Diverging	Oxy		CMOcean
Diverging	Picnic		Plotly
Diverging	PiYG		ColorBrewer
Diverging	Portland		Plotly
Diverging	PRGn		ColorBrewer
Diverging	PuOr		ColorBrewer
Diverging	RdBu		ColorBrewer
Diverging	RdGy		ColorBrewer
Diverging	RdYlBu		ColorBrewer
Diverging	RdYlGn		ColorBrewer
Diverging	SmoothCoolWarm		Kenneth Moreland
Diverging	Spectral		ColorBrewer
Diverging	TealRose		CARTO
Diverging	Temps		CARTO
Diverging	Topo		CMOcean
Diverging	Tropic		CARTO
Qualitative	Accent		ColorBrewer
Qualitative	Alphabet		Polychrome
Qualitative	Antique		CARTO
Qualitative	Bold		CARTO
Qualitative	D3		d3.js
Qualitative	Dark2		ColorBrewer
Qualitative	Dark24		Polychrome
Qualitative	G10		Plotly
Qualitative	Light24		Polychrome
Qualitative	Paired		ColorBrewer
Qualitative	Pastel		CARTO
Qualitative	Pastel1		ColorBrewer
Qualitative	Pastel2		ColorBrewer
Qualitative	Plotly		Plotly
Qualitative	Prism		CARTO
Qualitative	Safe		CARTO
Qualitative	Set1		ColorBrewer
Qualitative	Set2		ColorBrewer
Qualitative	Set3		ColorBrewer
Qualitative	T10		Plotly
Qualitative	Tab10		Tableau
Qualitative	Tab20		Tableau
Qualitative	Tab20b		Tableau
Qualitative	Tab20c		Tableau
Qualitative	Vivid		CARTO
Sequential	AgGrnYl		Plotly
Sequential	AgSunset		Plotly
Sequential	Algae		CMOcean
Sequential	Amp		CMOcean
Sequential	BlackBody		Kenneth Moreland
Sequential	BlackbodyAlt		Plotly
Sequential	BlackBodyExtended		Kenneth Moreland
Sequential	Blues		ColorBrewer
Sequential	BluGrn		CARTO
Sequential	BluYl		CARTO
Sequential	BrwnYl		CARTO
Sequential	BuGn		ColorBrewer
Sequential	BuPu		ColorBrewer
Sequential	Burg		CARTO
Sequential	BurgYl		CARTO
Sequential	Cividis		matplotlib
Sequential	CubeYF		MyCarta
Sequential	DarkMint		CARTO
Sequential	Deep		CMOcean
Sequential	Dense		CMOcean
Sequential	Electric		Plotly
Sequential	Emrld		CARTO
Sequential	GnBu		ColorBrewer
Sequential	Gray		CMOcean
Sequential	Greens		ColorBrewer
Sequential	Greys		ColorBrewer
Sequential	Haline		CMOcean
Sequential	Hesperia		Peter Karpov
Sequential	Hot		Plotly
Sequential	Ice		CMOcean
Sequential	Inferno		matplotlib
Sequential	Jet
Sequential	Kindlmann		Kindlmann et al.
Sequential	KindlmannExtended		Kindlmann et al.
Sequential	KovesiBGYW		CET
Sequential	KovesiKRYW		CET
Sequential	Lacerta		Peter Karpov
Sequential	Laguna		Peter Karpov
Sequential	Magenta		CARTO
Sequential	Magma		matplotlib
Sequential	Matter		CMOcean
Sequential	Mint		CARTO
Sequential	Oranges		ColorBrewer
Sequential	OrRd		ColorBrewer
Sequential	OrYel		CARTO
Sequential	Peach		CARTO
Sequential	PinkYl		CARTO
Sequential	Plasma		matplotlib
Sequential	PlasmaModified		Peter Karpov
Sequential	Plotly3		Plotly
Sequential	PuBu		ColorBrewer
Sequential	PuBuGn		ColorBrewer
Sequential	PuRd		ColorBrewer
Sequential	Purp		CARTO
Sequential	Purples		ColorBrewer
Sequential	PurpOr		CARTO
Sequential	Rain		CMOcean
Sequential	RdPu		ColorBrewer
Sequential	RedOr		CARTO
Sequential	Reds		ColorBrewer
Sequential	Solar		CMOcean
Sequential	Speed		CMOcean
Sequential	Sunset		CARTO
Sequential	SunsetDark		CARTO
Sequential	Tarn		CMOcean
Sequential	Teal		CARTO
Sequential	TealGrn		CARTO
Sequential	Tempo		CMOcean
Sequential	Thermal		CMOcean
Sequential	Turbid		CMOcean
Sequential	Turbo		Google AI
Sequential	Viridis		matplotlib
Sequential	YlGn		ColorBrewer
Sequential	YlGnBu		ColorBrewer
Sequential	YlOrBr		ColorBrewer
Sequential	YlOrRd		ColorBrewer

Colormap credits

• Default colormaps include all ColorBrewer 2.0 color maps;
• Smooth Cool Warm, Bent Cool Warm, Black Body, Kindlmann, Extended Kindlmann (https://www.kennethmoreland.com/color-advice/)
• Tableau colour maps
• Colormaps from Peter Karpov.
• Turbo from https://ai.googleblog.com/2019/08/turbo-improved-rainbow-colormap-for.html
• "Why We Use Bad Color Maps and What You Can Do About It." Kenneth Moreland.
• "Beautiful colormaps for oceanography