If you want to choose a color palette for UI properly, the least you have to do is put them on a lofi UI or grayscale the entire UI on Figma, Adobe XD, or similar platforms to get a better idea of what those colors will actually look like on a product. This process can take a long time (and time is gold!). Clients (and anyone, really) often have very different impressions from the actual implementation of a color palette. So, there is a lot of back-and-forth in the process of design. We should hope to minimize that. Another problem is that colors are usually presented differently on different devices and monitors due to the difference in their calibrations. So you might choose a color on your desktop and notice it's completely different on mobile. These differences should be addressed before the entire process of design and development so as to avoid any issues further on. A platform that allows for you to visualize and realize all your color choices can fix the problems mentioned above. You'd say that we already have design platforms (e.g., Figma) for that. That is absolutely correct, and ultimately, you should try out the color palette on your own design yourself. To present the color palette on a design platform, like Figma, you'd have to create a quick prototype and try to view it on different platforms, share it with clients, etc. You can already imagine how long that takes. Instead, you can share input your favorite colors on Realtime Colors and instantly share the link to a real website showcasing those colors.