I'd like to do something similar to CSS linear-gradient, e.g.
background: rgb(2,0,36);
background: linear-gradient(153deg, rgba(2,0,36,1) 0%, rgba(26,117,85,1) 35%, rgba(0,212,255,1) 100%);
To get support on all platforms, we need something like https://github.com/react-native-community/react-native-linear-gradient
In the meantime, you can circumvent this by using an appropriate SVG background image.