There is a lot of confusion about the uniforms of the carabiniers. According to the reglement white with light blue facings (that's for sure!). But it seems that also the reversed colours at least by some troopers were worn (to which extend is unclear, maybe only caused by shortages in available cloth; or these were the light blue off duty uniforms to save the white ones from tear and wear).

Take a look at this link:
https://www.napolun.com/mirror/napoleonistyka.atspace.com/French_Cavalry.html#frenchhorsecarabiniers

For Waterloo the latest generally accepted opinion is light blue faced white. And I know some figure enthousiasts for this battle which recoloured their miniatures.

Kind Regards
Thomas