Labels aren't colored properly

I can't get coloring labels in my inventory GUI to work.

Here's my code:

 public Color nameColor = Color.red;
     public Color amountColor = Color.green;
     bool InventoryButtonWidget(int x, int y, Inventory inv, int index) {
         GUIStyle leftLabel = GUI.skin.label;
         GUIStyle rightLabel = GUI.skin.label;
         rightLabel.font = GUI.skin.font;
         leftLabel.font = GUI.skin.font;
         leftLabel.alignment = TextAnchor.MiddleLeft;
         leftLabel.font.material.color = nameColor;
         rightLabel.alignment = TextAnchor.MiddleRight;
         rightLabel.font.material.color = amountColor;
         bool temp = GUI.Button(new Rect(x,y,64,64),inv.getItemIcon(index));
         GUI.Label(new Rect(x+GUI.skin.button.margin.left,y+64-24,64-GUI.skin.button.margin.left - GUI.skin.button.margin.right,24),inv.getItemName(index),leftLabel);
         int amount = inv.getItemAmount(index);
         if (amount>1) { //do not draw item amount if we just have one item
             GUI.Label(new Rect(x+GUI.skin.button.margin.left, y+GUI.skin.button.margin.top,64-GUI.skin.button.margin.left-GUI.skin.button.margin.right,24),amount.ToString(),rightLabel);
         }
         return temp;
     }

As you can see, nameColor and amountColor defaults to red and green respectively, but when showing it in game, it is white for some reason. Can you help me?