Often people only know about modern hula (auana) which is a bit softer and more graceful (in a diffferent way) than anicent hula (kahiko). They are not aware of the depth of knowledge, skill, and symbolism involved in hula. Its more than just being a good dancer, dancers must emote the meaning of the dance.
The color of the costume and adornments should relate to the topic, location, person honored or meaning of the dance. Hawaiian history is passed down orally (not written) and through song. The islands are symbolized by specific colors, the ocean can be blue for the ocean, or green for the forest. There are many more that those who study hula spend years studying and learning but this gives you a glimmer of what’s involved.
You may have noticed all of the leis, head wrist and ankle adornments are mae by the dancer, fresh flowers, ferns, leaves and vines. I believe there was only one group that made the dried raffia adornments. Fabric was often hand stamped, all of this is included in the assessments of the judges as well as the actual dance.