Add sprite renderer extensions and fix color calcs

[HagamosVideojuegos]

I have added the colors extension for the SpriteRenderer based on Graphic and have fixed the calculation of the color transition.

The calculation uses the opposite color that you want to arrive at with the current calculation.

Example:

private void Start()
{
    GetComponent<SpriteRenderer>()
        .TweenColor(Color.green, 1f, EasingFunctions.Linear, TweenSettings.CycleOnce, true, false)
        .StartFrom(Color.white);
}