The Maya cultivated marigolds long before the French. After all, the ancestors of modern French hybrid marigolds, Tagetes patula, are endemic to Mexico and Guatemala. French horticulturists merely developed the hybrids that are now most popular. The largest might grow a foot high and wide. Otherwise, almost all grow lower as compact bedding plants.
Although many varieties of French hybrid marigold are available, their floral color ranges only through yellow, orange and red. Ruddy brown is merely dark orange. Creamy white is merely very pale yellow. Combinations of color within this minimal range are amazing nonetheless. White is rare only because richer traditional colors remain so very popular.
French marigolds are technically warm season annuals. With frequent deadheading and grooming, they can bloom from spring until frost. However, since they perform best while young, they are more popular as a shorter term annual. They often replace warm season annuals that finish a bit early, while the weather is still too warm for cool season annuals.