Radical French tips were never meant to be blended or even have a smile line ... IT was left up to the technician to reduce the well and create her own smile line when doing so. They are meant to be applied to the merest sliver of free edge and for white powder to be used over them in zone 1. That has always been CND teaching with Radical French Tips.With the Radical French tips...which don't have a great smile line...I always tended to reduce the contact area by cutting out a deeper smile with a pair of curved scissors. You could also file it out.
It is the contact are you are saying is a different colour, (because it is thinner).
I always tended to use my white l&P ovet the tip anyway then you would not see this ghost/contact area, and it also meant I was still applying a smile line albeit using the tip as a guide.HTH
Or as Nailzoo says you could try well less tips.