code: package org.gridkit.jvmtool.stacktrace.analytics.flame;
  
  import java.awt.Color;
  
  import org.gridkit.jvmtool.stacktrace.GenericStackElement;
  import org.gridkit.jvmtool.stacktrace.StackFrame;
  
  public class DefaultColorPicker implements FlameColorPicker {
  
      @Override
      public int pickColor(GenericStackElement[] trace) {
  
          if (trace.length == 0) {
              return 0xFFFFFF;
          }
  
          StackFrame sf = (StackFrame) trace[trace.length - 1];
  
          int c = hashColor(12, 10, sf);
  
          return c;
      }
  
      public static int hashColor(int baseHue, int deltaHue, StackFrame sf) {
          int hP = packageNameHash(sf.getClassName());
          int hC = classNameHash(sf.getClassName());
          int hM = sf.getMethodName().hashCode();
  
          int hue = deltaHue == 0 ? baseHue : baseHue + (hP % (2 * deltaHue)) - deltaHue;
          int sat = 180 + (hC % 20) - 10;
          int lum = 220 + (hM % 20) - 10;
  
          int c = Color.HSBtoRGB(hue / 255f, sat / 255f, lum / 255f);
          return c;
      }
  
      public static int hashGrayColor(StackFrame sf) {
          int hC = classNameHash(sf.getClassName());
          int hM = sf.getMethodName().hashCode();
  
          int hue = 0;
          int sat = 0;
          int lum = 220 + ((hM + hC) % 20) - 10;
  
          int c = Color.HSBtoRGB(hue / 255f, sat / 255f, lum / 255f);
          return c;
      }
  
      private static int packageNameHash(String className) {
          int c = className.lastIndexOf('.');
          if (c >= 0) {
              return className.substring(0, c).hashCode();
          }
          else {
              return 0;
          }
      }
  
      private static int classNameHash(String className) {
          int c = className.lastIndexOf('.');
          if (c >= 0) {
              className = className.substring(c + 1);
          }
  
          c = className.indexOf('$');
          if (c >= 0) {
              int nhash = className.substring(0, c).hashCode();
              int shash = className.substring(c + 1).hashCode();
              return nhash + (shash % 10);
          }
          else {
              return className.hashCode();
          }
      }
  }
  