Q: i os10 clock background

I have an iPhone 6s and I updated to I OS10 yesterday - now my clock background is dark with light lettering - I need for it to go back to light background with dark lettering - I know this may seem petty, but the darker background with white lettering hurts my eyes - which gives me headaches. I don't drive at night for the same reason - is there a way to change back to a lighter background with darker lettering?

THANKS for any help/advice