If you're looking for a scratch cake, I hope someone can help you - I stopped making scratch angel food cakes years ago. I have the following on my "try soon" list so I can't give a whole-hearted recommendation yet. I could find nothing with lemonade but two similar recipes use thawed frozen orange juice concentrate. Have you tried pink lemonade concentrate or just pink lemonade for the liquid? Anne Byrn's Cake Mix Doctor cookbook provides the following suggestions and I'll also include her Orange Almond Angel Food Cake recipe:

Anne's Six Ways to Tweak an Angel Food Cake:
1) Toasted coconut: Add 1/2 cup.
2) Unsweetened cocoa powder: Add up to 1/4 cup.
3) Pure almond extract: Add 1 teaspoon.
4) Peppermint schnapps: Add 2 tablespoons.
5) Coffee: Add up to 1/4 cup, brewed & cooled, replacing the same amount of the water.
6) Orange juice concentrate: Add up to 1/4 cup, replacing the same amount of water.

Orange Almond Angel Food Cake

1 16-oz pkg angel food cake mix
1 cup water
1/4 cup thawed frozen orange juice concentrate
1 tsp pure almond extract

I'll skip all the instructions since I think they're about the same as you'll see on the box. Bake at 325 deg. in an ungreased 10" tube pan until it is deep brown and springs back when lightly pressed with your finger, 38 to 42 minutes. Remove the pan from the oven and immediately turn it upside down over the neck of a glass bottle to cool for at least 1 hour.

I used orange juice ALONG WITH 1 TBSP orange zest to a doctored pound cake and it made such a difference. I want to make the orange angel food but I think I'll add some zest as well.

I also printed a copy of an Orange Angel Cake from Betty Crocker's site - It calls for 1 pkg angel cake mix and 1-1/4 cups orange juice and said to bake it at 350 deg. for 37 to 47 min. until dark golden brown. It said to cool upside down 2 hours.

...Could you try using pink lemonade for the liquid and adding 1 tsp. of lemon zest?

Still another interesting recipe I copied called for a boxed angel food cake mix and 1 20-oz can of crushed pineapple, UNDRAINED.

Sure wish I had tried some of these but they just haven't gotten to the top of the list. And I suspect you have tried the juice thing since you said you haven't been able to duplicate what you're looking for.
But good luck!