android color between two colors, based on percentage?

Question

I would like to calculate the color depending on a percentage value:

float percentage = x/total;
int color;
if (percentage >= 0.95) {
  color = Color.GREE         


        

Answer 1

I just wanted to update Mark Renouf's answer to handle alpha channel as well:

private float interpolate(float a, float b, float proportion) {
    return (a + ((b - a) * proportion));
}

/**
 * Returns an interpolated color, between a and b
 * proportion = 0, results in color a
 * proportion = 1, results in color b
 */
private int interpolateColor(int a, int b, float proportion) {

    if (proportion > 1 || proportion < 0) {
        throw new IllegalArgumentException("proportion must be [0 - 1]");
    }
    float[] hsva = new float[3];
    float[] hsvb = new float[3];
    float[] hsv_output = new float[3];

    Color.colorToHSV(a, hsva);
    Color.colorToHSV(b, hsvb);
    for (int i = 0; i < 3; i++) {
        hsv_output[i] = interpolate(hsva[i], hsvb[i], proportion);
    }

    int alpha_a = Color.alpha(a);
    int alpha_b = Color.alpha(b);
    float alpha_output = interpolate(alpha_a, alpha_b, proportion);

    return Color.HSVToColor((int) alpha_output, hsv_output);
}