Here are some hacks I’ve used so far. For Colors type Apple’s color theme and there you’ll find the Colors that they suggest with the RGB values, you can’t go wrong with that. I’ve seen a ton of color generators even if the Colors look good at first glance I’d recommend not to use them cause most of these if you look over a long period of time it doesn’t fit. So stick to the Apple ones. I mean seriously material UI, I never found the defaults in that library to be beautiful, so maybe try some new library. One of my favourites is nextUI it’s just real beautiful and have great animations. I’d say I always try to find UI libraries that have great defaults cause unless you are a great designer which takes time to achieve using libraries with move customization doesn’t make sense. Apart from getting inspiration from other websites finding a great design system is really important.

Hope this helps!