In this review, the process of forming iridescent, structurally colored films from suspensions of cellulose nanocrystals (CNCs) is summarized and the mechanisms underlying the chemical and physical phenomena at each stage in the process explored.

In this review, the effects of various factors involved in the preparation of nanocellulose films on structural color, the color response of the nanocellulose films to environmental factors, and the structural design of cellulose nanomaterials in the field of color development are summarized.

Here, we demonstrate a universal yet economical approach to prepare cellulose structural-color pigments with different sizes. A combined ultrasonication and grinding treatment is explored to adjust the pigment colors as well as control the iridescence-to-non-iridescence transition that depends on the pigment size.

Intended as coatings for solar cells, we demonstrate a transreflective cellulose material with minimal solar absorption that generates color by wavelength-selective reflection, while it transmits other parts of the solar spectrum.

Herein, we propose a 3D-printable multifunctional cellulose material system with structural colors, prepared from dispersing carbon nanotubes (CNT) and cellulose nanofibrils (CNF) into an HPC aqueous solution, as shown in Figure 1A.