Add Color classes for use with AddressableLED (#2127)

Both floating point and 8-bit integer classes are included, as well as a wide selection of color constants.

Co-authored-by: Austin Shalit <austinshalit@gmail.com>

wpiutil/src/main/java/edu/wpi/first/wpiutil/math/MathUtil.java

@@ -12,6 +12,17 @@ public final class MathUtil {
     throw new AssertionError("utility class");
   }
 
+  /**
+   * Returns value clamped between low and high boundaries.
+   *
+   * @param value Value to clamp.
+   * @param low   The lower boundary to which to clamp value.
+   * @param high  The higher boundary to which to clamp value.
+   */
+  public static int clamp(int value, int low, int high) {
+    return Math.max(low, Math.min(value, high));
+  }
+
   /**
    * Returns value clamped between low and high boundaries.
    *