The French Rugby Federation (FFR) announced on Thursday it will trial the use of coloured bibs in training sessions among amateur clubs in an attempt to reduce the risk of head injuries.
The lower third of the vest is orange to encourage players to tackle nearer the waist, with red and green segments near the shoulders and hips to help with technique.
There will be 49 lower league sides involved in the experiment which will last for eight weeks until the end of the currently postponed season and will be continued if the coronavirus pandemic continues to put the campaign on hold.
All amateur clubs in France are currently sidelined, with training due to recommence this week.
"It's the preparation of a tackle. If you don't set it up well then you can be in a position where the head is positioned on the wrong side and that's where the risks of concussion are increased," FFR's technical director Didier Retiere told a press conference.
In March 2019, the FFR announced law changes for clubs below the fifth-tier which included lowering the height of the tackle to the waist and banning collisions by two players.
Four young rugby players have died since May 2018 in France including Stade Francais teenager Nicolas Chauvin after breaking his neck and Aurillac's 21-year-old Louis Fajrowski following a heavy tackle.