There is little information on the subject - at least not easily found. Looks like ~15-20% of serving troops are Muslim. I would assume that this group is almost 100% Arabic or African

But that sort of behavior is untenable today due to the Army’s growing Muslim contingent, which represents around 10 to 20 percent of France’s military population.

Why French military may be more tolerant of Muslims than French society.

Yet an estimated 15 percent of the French military has roots in the Muslim world.

Mission Critical: Advancing Diversity in U.S. and European Militaries

This article suggests that the proportion of non-White soliders in the French military is roughly proportional to the overall level in French society. It was published in 2009, so the rate will be higher now.

France has the largest Muslim population in Europe, estimated at between five and seven million people, or about 7 to 10 per cent of the French population.Statistics are not available because, officially, the state does not collect data according to ethnicity, religion or race. But the ratio of Muslims in the military, including the national police or gendarmerie, mirrors that in the population as a whole, according to Capt. Bouharb and other officials.

France's army embraces its Muslim soldiers

Not much data to go on. Looks like the 20% Muslim number you were cited is credible. I would doubt that the 40% Black number is accurate though