In general the Les Beiges powders are among the sheerest of the sheer when it comes to pressed powders. They aren’t quite as sheer as MAC Blot Powders though (which I always found chalky-looking). You can definitely layer the Les Beiges over tinted moisturizers or foundations. Buffing in a circular motion with a denser brush helps build color.
I would say the Les Beiges are most similar in concept to the discontinued Poudre Douce Soft Pressed Powders even though these only came in lighter shades. Pêche Tendre 20 (no longer available in the US) has a more glowy finish with visible shimmer. Les Beiges No. 20 has no visible shimmer and goes on the skin more pinkish.
Below you can see that the Double Perfection Lumiere in 20 Beige has significantly more coverage than the Les Beiges powders and that in general the darker Les Beiges powders are quite a bit warmer in undertone. They aren’t quite as brown as MAC Golden Bronzer (which also has more of a glow at a cheaper price) but Les Beiges have a similar natural finish.
You can find Les Beiges now at Nordstrom.