When a CD (Compact Disc used in audio and video systems) is seen in sunlight, rainbow like colours are seen. This can be explained on the basis of the phenomenon of

The rainbow colors seen from a CD arise because the microscopic, regularly spaced spiral grooves act as a reflection diffraction grating: white light reflecting from the closely spaced tracks is diffracted so different wavelengths satisfy the grating condition at different angles, separating the colors [1]. The effect is observed in reflection (not transmission through the disc) and the colors result from wavelength-dependent constructive interference of the reflected beams from neighboring grooves, producing a spectrum like a diffraction grating output [2]. The grating behavior of the pits/lands on CDs is well explained by the grating equation relating groove spacing and wavelength to diffraction angle, accounting for the ordered colored bands.

Sources

1. [1] https://openstax.org/books/physics/pages/17-2-applications-of-diffraction-interference-and-coherence
2. [2] https://www.exploratorium.edu/explore/science/activity/reflecting-rainbows