Generate best colors

Colorize.java

package one.xcorp.myeye.core.utils;

import android.graphics.Color;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.graphics.drawable.Drawable;
import android.support.annotation.ColorInt;

public class Colorize {

    public static final float HSV_SATURATION_DARK = 0.99f;
    public static final float HSV_VALUE_DARK = 0.99f;

    public static final float HSV_SATURATION_DEFAULT = 0.5f;
    public static final float HSV_VALUE_DEFAULT = 0.95f;

    public static final float HSV_SATURATION_LIGHT = 0.3f;
    public static final float HSV_VALUE_LIGHT = 0.99f;

    private final int offset;
    private final int count;

    private float saturation = HSV_SATURATION_DEFAULT;
    private float value = HSV_VALUE_DEFAULT;

    private int position;

    public Colorize() {
        this(0, -1);
    }

    public Colorize(int offset, int count) {
        this.offset = offset;
        this.count = count > 0 ? count : Integer.MAX_VALUE;
    }

    public int getOffset() {
        return offset;
    }

    public int getCount() {
        return count;
    }

    public float getSaturation() {
        return saturation;
    }

    public Colorize setSaturation(float saturation) {
        this.saturation = saturation;
        return this;
    }

    public float getValue() {
        return value;
    }

    public Colorize setValue(float value) {
        this.value = value;
        return this;
    }

    public int getPosition() {
        return position;
    }

    public Colorize setPosition(int position) {
        if (position > count - 1) {
            throw new IndexOutOfBoundsException("Specified position exceeds total colors count");
        }

        this.position = position;
        return this;
    }

    /**
     * Generated random color had to be "good looking".
     *
     * @return color
     */
    @ColorInt
    public int generateColor() {
        // use random init value 0.038764358f and golden ratio 0.618033988749895f
        float hue = (0.038764358f + 0.618033988749895f * offset + position++) % 1;
        int color = Color.HSVToColor(new float[]{hue * 360, saturation, value});

        if (position > count - 1) {
            position = 0;
        }

        return color;
    }

    /**
     * Generate text color had to be "good looking".
     *
     * @param color background color
     * @return text color
     */
    @ColorInt
    public static int getContrastColor(@ColorInt int color) {
        // Counting the perceptive luminance - human eye favors green color...
        double a = 1 - (0.299 * Color.red(color) + 0.587 *
                Color.green(color) + 0.114 * Color.blue(color)) / 255;
        return a < 0.5 ? Color.BLACK : Color.WHITE;
    }

    /**
     * Change drawable color.
     *
     * @param drawable drawable
     * @param color    color
     * @return mutate drawable with specified color
     */
    public static Drawable colorize(Drawable drawable, @ColorInt int color) {
        if (drawable != null) {
            drawable = drawable.mutate();
            drawable.setColorFilter(
                    new PorterDuffColorFilter(color, PorterDuff.Mode.SRC_IN));
        }

        return drawable;
    }
}