Wrong text color in mate's global menu

Menu list items should use different color from menu labels because menu background popup is white and not dark like the panel.

Keep the light color for menu labels (file, edit, view, help...) because the panel color is dark with this theme and change the color of menu list items into a dark color because popup menu is white so that it'll be readable.

This issue is inherited from Arc theme.

I don't know if it's a gtk limitation in which you can't have different color for menu labels and menu items.

Mint Y and Mint X theme

Arc theme