The sky is the give-a-way. It is has a heavy cyan cast (or at least it does looking at it on my screen) I don't know what filtration units your enlarger is callibrated in, but if it is in Kodak units I would start of by removing 10 units of magenta and 10 units of yellow. As cyan is the opposite of red this should correct your problem and brighten up the reds. If it still isn't correct remove another 5 units of each, or if you have gone too far ADD 5 units of each. You are not bound by any protocol to remove 10's or 5's in units you can remove or add whatever you wish, even singles if you are prepared to fiddle.
You will of course have to do test strips again and consider over exposure will alter the balance so it has to be correct.