Why does a mirror look silvery rather than colored?
A mirror works by bouncing light back toward you. When a surface reflects most of the visible light across the whole range of colors fairly evenly, your eye receives a balanced mix and reads it as neutral or silvery rather than as a distinct hue. The reflective, mirrored finish on a rearview mirror, for example, is described as producing a complex reflectivity that complicates how its appearance is measured [3]. In other words, the mirror's own appearance is dominated by what it reflects, not by a pigment of its own.
This is why a mirror in a white room looks white-ish and a mirror facing a red wall looks reddish. The mirror is not changing color; it is faithfully passing along the light it receives. The silvery look is the signature of broad, even reflection rather than a tint.
Can a mirror be made to reflect a specific color?
Yes—but only by engineering the mirror-like structure itself. One approach uses a "meta-mirror" built into an optical cavity, a layered structure that traps and reflects light in a controlled way. In such a device, the reflected color can depend on the polarization of the incoming light—meaning the color you see changes with the orientation of the light's oscillation—so the structure produces distinctly different colors under different polarization conditions [1]. That is a designed effect of a special artificial structure, not a property of an everyday mirror.
A related idea appears in plasmonic mirror color filters, which are mirror-like surfaces engineered to transmit or reflect selected colors. Researchers optimize the geometry of these nanostructures to tune which colors pass through, using computer simulations to search a five-dimensional design space [2]. Here too, the color is a product of deliberate nanoscale design rather than something intrinsic to mirrors in general.
So what is the color of a mirror?
The honest answer depends on which mirror you mean. A household or rearview mirror has no fixed color: it reflects the full spectrum fairly evenly and takes on the colors of its surroundings, which is why it reads as silvery [3]. A specially engineered mirror-like surface can be tuned to reflect or transmit particular colors, and its color can even depend on the polarization of the light hitting it [1][2].
The artistic use of mirror color choices in painting is a separate matter: there, color is a compositional decision by the artist rather than a physical property of a reflective surface [4]. That distinction matters, because it shows how easily "mirror color" can mean either a physical reflection or a chosen representation. For the physical question, the practical takeaway is that an ordinary mirror is colorless in itself—its appearance is borrowed from the world it reflects.
Sources used in this answer
Decoupled polarization response in a meta-mirror-assisted structural color cavity
A meta-mirror-assisted optical cavity can produce polarization-dependent reflected colors, so its color changes with the polarization of the illuminating light.
Optimizing Photonic Nanostructures via Multi-fidelity Gaussian Processes
Plasmonic mirror color filters can be optimized through simulation to tune their transmission of specific colors across a five-dimensional design space.
Defect detection method for curved and reflected paint surfaces of rearview mirrors
Rearview mirrors have a curved, mirrored color design whose complex reflectivity complicates automatic defect detection on their painted surfaces.
Cornfed & Queer
The paper discusses artistic painting techniques in which mirror color choices are used in depicting fabric and figures.