The blue with thin red and white stripes is the old one... Originally appearing in Camospecs: A Guide to Regimental Paint Schemes, this is the classic look. That book was printed in the late '80's. Typically, a newer product supersedes an older one when they conflict. In the late '90's we got the Field Manual series of books, detailing the various factions' military units around the in-universe year 3060. That book showed the Davion Guards in the new "French Flag" version of the scheme, with 5 vertical bands of colour. More recently, the cover for TRO:3145 Federated Suns showed the classic look again.
No in-universe dates or reasons for the changes have been given at this point. That leaves things fuzzy around the edges of when they would use which version of the scheme. When they started and stopped using the new version, or if they ever completely stopped using either version are unanswered questions. Given published material, it's safe to say the new version did not appear before the 4th Succession War (~3028), and it is likely that it was the primary one in use through the FedCom alliance period (-3067). Beyond that, I'm not going to hammer down anything as absolute.