Summary: This PR fixes the color of ReleaseChannel information in the WelcomeScreen, when user uses dark mode. I have decided to switch to `textColorSecondary` instead of `textColorPrimary` to emphasise a bit more the information, but I can change it to the primary color if you think it will fit there better. Also the font size has been adjusted to match the paragraph font size. ## Changelog * fix ReleaseChannel info in WelcomeScreen in dark mode Pull Request resolved: https://github.com/facebook/flipper/pull/3328 Test Plan: The change has been testes by running the desktop Flipper app locally from source. ## Preview #### Dark Mode (before & after) <img width="333" alt="Screenshot 2022-01-23 at 15 14 12" align="left" src="https://user-images.githubusercontent.com/719641/150682951-6e256054-d8d9-4293-8f76-4d67b654482f.png"> <img width="333" alt="Screenshot 2022-01-23 at 15 09 58" src="https://user-images.githubusercontent.com/719641/150682954-942eda7a-443d-4ca1-be51-b6d0036548cd.png"> #### Light Mode <img width="333" alt="Screenshot 2022-01-23 at 15 22 42" src="https://user-images.githubusercontent.com/719641/150683094-62983788-646e-4745-b9c0-3c7f7bea9787.png"> Reviewed By: aigoncharov Differential Revision: D33738596 Pulled By: lblasa fbshipit-source-id: 2fdd18871fbf9d1c215b58173932d57d5731948a
flipper-ui-core (TBD)
Flipper's UI, agnostic of Electron vs Browser.