Setting color of sprite, weird behaviour

I have a sprite, and when setting the color in this way it works fine.
Color new_color = Color.red;

When I set the color via RGBA it doesn’t:
Color new_color = new Color(255f,0f,0f,255f);

Any ideas?

According to the Color docs here:

http://docs.unity3d.com/ScriptReference/Color-ctor.html

The R, G, B, and A values are floats in the range of 0-1.