I am trying to improve my design side on web design. I have design a mobile app using a platform called ApplicationCraft which gives me mobile 5 mobile themes (colours) and have created a 'nice' looking app using the green theme.

I allow the client to add their own logo & banner which then conflicts with the green theme I am using.

I can use CSS to change the colours of the theme so I need to know if there is a 'Standard neutral' range of colours to achieve this.

This is my current screen: