Can't change GameObject color via script?

Question

I have a canvas for UI, with an image the same size of the canvas. The Image has an rgba of 0,0,0,0 , making it invisible (because the a is 0). I want to have the image fade into black from a script. Here is the code I am using:

public class NavigationC : MonoBehaviour {
    public Image screen;
    float fadeTime = 3f;
    Color colorToFadeTo;

    void StartGame()
    {
        colorToFadeTo = new Color(0f, 0f, 0f, 255f);
        screen.CrossFadeColor(colorToFadeTo, fadeTime, true, true);
    }
}

Now, this doesn't do anything when executed. But when I change the image's a value manually in unity so that the image becomes visible, I can see the script changing the image's color. So the script does work, it just isn't visible because the a value is not being changed by the script. So how can I make the image fade from invisible to black?

Answer 1

Here is your problem:

new Color(0f, 0f, 0f, **255f**);

The Color constructor parameter takes values from 0f to 1f but you are passing 0f to 255f range value to it.

That should be:

colorToFadeTo = new Color(0f, 0f, 0f, 1f);

If you want to use the 0 to 255 range then you must divide it by 255.

colorToFadeTo = new Color(0f, 0f, 0f, 255f/255f);

---

Also, there is Color32 which can take values between 0 and 255. You can use that then covert it back to color.

Color32 color32 = new Color32(0f, 0f, 0f, 255f));
Color color = color32;