You can add rules on the iCloud.com site that apply server side before Mail is opened on any device. I use that to send newsletters and other similar things to a specific folder to unclutter the inbox.
I don’t apply colors to emails but do have a number of rules to move them into different folders. I originally set up the rules on iCloud.com so they would be in effect when reading on my iPad. I now run them on my M1 iMac which runs all the time. Much easier to edit and add new rules.