I want to change the color of a GUI.Label using script

  GUI.skin.label.hover.textColor = Color.blue;
  GUI.skin.label.normal.textColor = Color.black;
  GUI.skin.label.active.textColor = Color.yellow;

I want to change the color of label using scripts. The color is changing in GUI.skin in in inspector.

When using above script but it is not not working for label and box in game mode. I don't want to change the color using applying directly in skin in inspector. I want change through scripts.