Quote from Microsoft, Custom list and library templates are currently not supported; including but not limited to lists such as Announcements, Contacts and Tasks.
We could create a responsive layout to respond to different devices or window sizes via Disable Scale to fit.
Reference: Create responsive layouts in canvas apps
1.Create new txt file and add this code (put your color code)
2.Save file as for ex buttonColor.txt
3.Upload file to ...
To align your cell to the right you can modify the last bit of your JSON:
To get just the integer bit you could do the following:
Adjust for correct decimal sign...