Croissant Browning Issue

I run a small commissary where I make tons of viennoiserie and other breakfast pastry for coffee shops. We laminate about 15 books of dough a week and bake off about 100 croissants (of different variety) everyday. With our traditional dough, we make a ham & gruyere, almond, cinnamon roll, fig and goat cheese (like a Danish almost) and of course a plain croissant.

The plain croissants require another 10 to 15% more baking time to brown and even then, they don't really brown as well. I fear them getting too flakey, crumbly if I go to far with them.

We use a revent rotating oven. Its about 10lbs of dough to 4lbs tourage. Plugra. Combination of bread and AP flour. instant yeast. A combo of water and milk (liquid). and some malt syrup. Of course salt, sugar, etc

Everything gets the same egg wash of whole eggs, a little water and salt.

Should I play around with replacing the milk with water and using milk powder instead?

Thanks.

Jason