Alfa I think this would look awesome and work better in the tennis green or a green colour of some sort. Otherwise app and concept is a wkd idea!

Bravo Yea orange and white aren't a good comb for reading

Charlie Ide dark grap instad of white

Charlie Grey*

Charlie Use dark grey instead of white, sorry autocorrection

Foxtrot Good interface. Nice colors if it the client colors. By the way, what color relate to tennis game?

Golf I think the white is great as a stand out color I would suggest using a darker hue for the orange or a green similar to the submit button writhin this app. Cheers