This research was carried out following the preceding research on natural cellulose fabrics dyed with extract of fresh african marigold petals. Dyeability on fabrics was tested by dyeing with wool and silk which are natural protein fibers. Dyeing tests were carried out under different pH of the dye solution and mordants, examining the changes in the surface color, K/S value, and maximum absorption wavelength. The probability of improving dyeability was investigated by pre-mordanting with pre-treated chitosan. Wool fabrics showed color tone of medium or less saturation and brightness, in dark yellow color series. An orange color of high saturation was only obtained by tin mordanting. Wool showed higher K/S value than cellulose fibers. In summary, marigold dye has more affinity for protein fibers. It showed better dye effect in wool than silk. The chitosan pre-treatment and pre-mordanting lowered the K/S value of wool, which showed that chitosan pre-treatment does not improve dye uptake. However, different from the dyeing carried out by pre-mordanting without pre-treatment with chitosan, more diversified colors could be obtained by mordants. Therefore, for the dyeing natural protein fibers with marigold extract, post-mordanting does not require chitosan pre-treatment. However, pre-mordanting with chitosan pre-treatment could implement diverse colors. Considering its dyeing behaviors which are similar in both natural cellulose and protein fibers, african marigold extracts can be evaluated as a stable and highly practical dye.