The menu item of the current page takes the same color as the ‘Color 2’ option by default. It sounds like you have made the menu background the same as this color.
Anyway, to change the current page menu item to a different color, add this CSS at Customize > Additional CSS:
#primary-menu li.current-menu-item > a {
color: #e08b8b;
}#e08b8b is the standard ‘Color 2’ color, so change this to any color you want.