There are many sites to help with your UI/UX for Power Apps development, but here are my favourite online resources. As well as giving you some great ideas they’ll also save lots of time with pre-written code!
Online Resources UI/UX for Power Apps
UI/UX Best Practise
There are many aspects to consider when creating excellent UI and UX. Here are a couple of sites that are well worth visiting regularly to develop skills, knowledge and understanding of best practise
uxmatters.com: Great articles on best practise relating to UX
material.io: Created by google. Pick a primary or secondary color and create a complementary palatte of colors, including text colors. Another great feature is the Accessibility tab that flags any accessibility issues with the colors you’ve chosen. You can also create a Dark Mode. This site is a great resource with articles and guidance on other aspects of UI/UX including typography, motion, sounds etc
coolors.co: Many color palletes to choose from. You can add additional colors or tweek existing palettes. You can also check your chosen scheme for color blindness. Once finalised, the design can be exported as a PDF, SVG, CSS or several other formats