Check your state laws regarding lighting. Most likely they require running lights visible from the rear to be red, front running lights yellow, and turn signals yellow, and that may even be federal rule, I'm not sure.
It varies by state but for most part you are not allowed to have amber rear facing running lights but you can have red rear facing running lights. Given that I've been converting my rear turns into running lights since the 80's and have yet to be stopped or ticketed for having amber rear facing running lights on any of my bikes through a good number of states. Now that is not to say the "YOU" will not get stopped and ticketed for it tomorrow but it has been my experience with LEO that if it appears to them that your only intension is to make your bike safer by way of being more noticeable that they are very tolerant of the law being bent. I have even been running "blue-dot" inserts in my brake lights and again have never been stopped or ticketed for them; I was in fact stopped the other day by a State Trooper for speeding and he never so much as said a word about my lighting variations and let me off with a warning about speeding.
To end this I use an SOS Priority Plus Brake Light Modulator/Turn Signal to Running Light Converter as while they are pricey they do make you much more visible by flashing your rear lights when you grab the brake.