The Windows 10 UWP version of Roblox, as found at @ https://www.microsoft.com/store/productId/9NBLGGGZM6WM uses the incorrect Roblox based on Roblox’s brand guidelines.(you can view them @ this url).
On page 11, it says…
DO NOT USE THE RED LOGO
Based on this information, you should update the splash screen on the UWP version of Roblox to use the correct logo.