To achieve the “purple” glow and really give your ride some individual flavor, you have 2 options. The end result is completely up to you and the effect you want to create whether that be more of a UV glow or an intense purple. UV or ultra violet is less bright than purple and actually closer to blue. A true purple light color would lie between blue and red.
UV is great for a soft purple glow but be warned, it will make any sort of white lint super visible.
Purple cathodes work really well and will give you that nice bright purple if that’s what you want to achieve.