Change GUILayout.Button font color

If you are using a GUILayout.Button instead of a GUI.Button you can use a GUIStyle:

 var style = new GUIStyle(GUI.skin.button);
 style.normal.textColor = Color.blue;
 GUILayout.Button("Label", style);

You can use GUI.contentColor to give a specific part an other color :

 function OnGUI() {

     GUI.Button("Standard Colored")
     GUI.contentColor = Color.red;  // Apply Red color to Button
     GUI.Button("Q button")
     GUI.Button("W button")  //...and so on for the rest Buttons
     GUI.contentColor = Color.withe;  //Make Buttons White color again 
     GUI.Button("White Colored Again")
 }

For information, the second solution works in the editor, the first only for in-game UI (which is depreciated and shouldn't be used AFAIK). :)