I need a PSD Template

We need a PSD template for creating mobile app screens. There are 5 screens: 1 splashscreen (downloadscreen), 3 swipescreens with info about the use of the app and 1 Aboutscreen (with links to downloading/website). All the text and objects and layout of the screens are standard, except for the colour of the buttons / text (orange items in this example) and placing of different customers’ logo on the Splashscreen and the Aboutscreen. Customers will have the possibility to give us 1 prefered colour(code) for the (orange) buttons and the (orange) tekst and they can send their logo. Ideally, we should be able to change the colour of the (orange) buttons and (orange) tekst into the given customer-colour. Is it possible to do this in PSD without having to change all the buttons and tekst seperately in each screen? Gradient/3D effects etcetera of the buttons should remain and also adjust to the different colour. I will send a psd “App icon Template” that I have, is it possible to make something like this so customer can directly see how the screens look on iPhone/iPad? Canvas/imagesize of the screens must be 1536(w) x 2048 (l). The screens are being used for both phones and tablets, so canvas-size (background) should be size of iPad-safezone and placing of all tekst and objects must be in the iPhone-safezone, I attach file with this resolution. The appearance of the images on the top-button (AR / download/flashlight / Qr-code) should match. (In this example I just grabbed a download / QR code and flashlight image) The AR-image on Swipe 1 is an existing file which I will send, the other images should be based on this one. Regarding the ‘About’, there should be a ‘close window’ symbol. In this example I used a simple X but an other suggestion is welcome. I will send the PSD template that I have used in this example, this is the design we would like the screens to be based on.