How can I change the highlighted color of a Unity button when it's clicked?

Question

I was playing around with buttons in Unity, and I wanted to see if I could change a button's highlighted color every time I clicked on it. I added a script in the same GameObject as a button component, and I had a changeColor function attached to the component's OnClick(). The function was in a ButtonScript class written like this:

public class ButtonScript : MonoBehaviour {
    public Button button;

    public void changeColor() {
        Debug.Log ("Changing highlighed color");
        int r = Random.Range (0, 255);
        int g = Random.Range (0, 255);
        int b = Random.Range (0, 255);
        Color currentColor = button.colors.highlightedColor;
        currentColor.r = r;
        currentColor.g = g;
        currentColor.b = b;
    }
}

I couldn't do button.colors.highlightedColor = new Color(r,g,b); because I got a "Consider storing the value in a temporary variable" error. When I tried a test play and clicked the button multiple times, the highlighted color didn't change. How can I make a function that changes a button's highlighted color when it's clicked, if it's possible?

Answer 1

I found that I needed to reassign currentColor to button.colors.highlighted afterwards. Oddly, I couldn't do button.colors.highlightedColor = currentColor, but I could reassign to the ColorBlock that button.colors returns (I got the idea from vexe's comment here). I also saw that the Color constructor takes floats from 0 to 1, not ints from 0 to 255 (even so, should've been Random.Range(0,256). Here's the class that worked for me:

public class ButtonScript : MonoBehaviour {
    public Button button;

    public void changeColor() {
        Debug.Log ("Changing highlighed color");
        float r = Random.Range (0f, 1f);
        float g = Random.Range (0f, 1f);
        float b = Random.Range (0f, 1f);
        ColorBlock colorVar = button.colors;
        colorVar.highlightedColor = new Color (r, g, b);
        button.colors = colorVar;
    }
}