Fig. 1. Schematic diagram of solution

Fig. 2. Scheme of surface pattern preparation using laserinduced periodic surface nanostructures

Fig. 3. Optical photographs of periodic nanostructures induced by nanosecond lasers at different fluences and scanning rates on mirror polished 304 stainless steel surfaces

Fig. 4. Effects of scanning rate and fluence on periodic pattern formation

Fig. 5. Effects of ripple sharpness and regularity on coloration. (a)--(c) Coloring renderings of three experimental conditions marked in figure 4 by circle, square, and triangle, respectively; (d)--(f) SEM images corresponding to Fig. 5(a)--(c); (g) frequency spectrum of Fourier transform of SEM images at k_y=0 μm^-1

Fig. 6. Fourier transform spectra of SEM image. (a)--(c) Two-dimensional Fourier transforms corresponding to Figs. 5 (e), (f), and (d), respectively

Fig. 7. Direction control of ripples by polarization rotator. (a) Optical images of periodic ripples with different orientation angle (φ); (b) periodic ripple direction angle (φ) dependence on rotation angle (α) of polarizer

Fig. 8. Effect of polarization direction on coloring

Fig. 9. Evolution of each component of RGB color space

Fig. 10. Flower patterns on surface of mirror polished 304 stainless steel based on periodic nanostructures. (a) Main body of flower appears orange-red when viewing angle is large; (b) flower body turns blue when viewing angle is reduced; (c) main body of flower shows green when viewing angle is further reduced

Fig. 11. Optical photographs of school logo on mirror polished stainless-steel surface

Fig. 12. Color effect of complex shapes on free-form surfaces