How to randomly receive a Material Design Color?

Question

Google has their Color - Guidelines, so how to randomly receive a color? Is there a way to specify a number from the table and receive a random color out of all colors of the ta

Answer 1

Here is a class I wrote. You can create your own material color palette or get a random color.

Example uses:

// get a random color.
int randomColor = MaterialColorPalette.getRandomColor("100");

// create your own material color palette
MaterialColorPalette myCustomPalette = new MaterialColorPalette(Color.CYAN);
int my200Color = myCustomPalette.getColor("200");

MaterialColorPalette.java

import android.graphics.Color;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Random;

public class MaterialColorPalette {

  public static final int RED_500 = 0xFFF44336;
  public static final int PINK_500 = 0xFFE91E63;
  public static final int PURPLE_500 = 0xFF9C27B0;
  public static final int DEEP_PURPLE_500 = 0xFF673AB7;
  public static final int INDIGO_500 = 0xFF3F51B5;
  public static final int BLUE_500 = 0xFF2196F3;
  public static final int LIGHT_BLUE_500 = 0xFF03A9F4;
  public static final int CYAN_500 = 0xFF00BCD4;
  public static final int TEAL_500 = 0xFF009688;
  public static final int GREEN_500 = 0xFF4CAF50;
  public static final int LIGHT_GREEN_500 = 0xFF8BC34A;
  public static final int LIME_500 = 0xFFCDDC39;
  public static final int YELLOW_500 = 0xFFFFEB3B;
  public static final int AMBER_500 = 0xFFFFC107;
  public static final int ORANGE_500 = 0xFFFF9800;
  public static final int DEEP_ORANGE_500 = 0xFFFF5722;
  public static final int BROWN_500 = 0xFF795548;
  public static final int GREY_500 = 0xFF9E9E9E;
  public static final int BLUE_GREY_500 = 0xFF607D8B;

  private static final List MATERIAL_PALETTES;

  private static final Random RANDOM = new Random();

  static {
    MATERIAL_PALETTES = new ArrayList<>();
    MATERIAL_PALETTES.add(new MaterialColorPalette(RED_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(PINK_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(PURPLE_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(DEEP_PURPLE_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(INDIGO_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(BLUE_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(LIGHT_BLUE_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(CYAN_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(TEAL_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(GREEN_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(LIGHT_GREEN_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(LIME_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(YELLOW_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(AMBER_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(ORANGE_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(DEEP_ORANGE_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(BROWN_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(GREY_500));
    MATERIAL_PALETTES.add(new MaterialColorPalette(BLUE_GREY_500));
  }

  public static int getRandomColor(String key) {
    return MATERIAL_PALETTES.get(RANDOM.nextInt(MATERIAL_PALETTES.size())).getColor(key);
  }

  /**
   * Lighten or darken a color
   *
   * @param color
   *     color value
   * @param percent
   *     -1.0 to 1.0
   * @return new shaded color
   * @see #shadeColor(String, double)
   */
  public static int shadeColor(int color, double percent) {
    return shadeColor(String.format("#%06X", (0xFFFFFF & color)), percent); // ignores alpha channel
  }

  /**
   * Lighten or darken a color
   *
   * @param color
   *     7 character string representing the color.
   * @param percent
   *     -1.0 to 1.0
   * @return new shaded color
   * @see #shadeColor(int, double)
   */
  public static int shadeColor(String color, double percent) {
    // based off http://stackoverflow.com/a/13542669/1048340
    long f = Long.parseLong(color.substring(1), 16);
    double t = percent < 0 ? 0 : 255;
    double p = percent < 0 ? percent * -1 : percent;
    long R = f >> 16;
    long G = f >> 8 & 0x00FF;
    long B = f & 0x0000FF;
    int red = (int) (Math.round((t - R) * p) + R);
    int green = (int) (Math.round((t - G) * p) + G);
    int blue = (int) (Math.round((t - B) * p) + B);
    return Color.rgb(red, green, blue);
  }

  private final HashMap palette = new HashMap<>();

  /**
   * @param primary
   *     the 500 color
   */
  public MaterialColorPalette(int primary) {
    palette.put("50", shadeColor(primary, 0.9));
    palette.put("100", shadeColor(primary, 0.7));
    palette.put("200", shadeColor(primary, 0.5));
    palette.put("300", shadeColor(primary, 0.333));
    palette.put("400", shadeColor(primary, 0.166));
    palette.put("500", primary);
    palette.put("600", shadeColor(primary, -0.125));
    palette.put("700", shadeColor(primary, -0.25));
    palette.put("800", shadeColor(primary, -0.375));
    palette.put("900", shadeColor(primary, -0.5));
    palette.put("A100", shadeColor(primary, 0.7));
    palette.put("A200", shadeColor(primary, 0.5));
    palette.put("A400", shadeColor(primary, 0.166));
    palette.put("A700", shadeColor(primary, -0.25));
  }

  public int getColor(String key) {
    return palette.get(key);
  }

  public void putColor(String key, int color) {
    palette.put(key, color);
  }

}

Just copy the class into your project and add the package declaration.