Classification – Odd one out (rainbow / spectral colors): Which color does not belong with the spectral (VIBGYOR) set: Green, Indigo, Pink, Violet?

Introduction / Context:
Many classification questions use the standard rainbow (spectral) colors remembered by the mnemonic VIBGYOR: Violet, Indigo, Blue, Green, Yellow, Orange, Red. Any color outside that set becomes a clean odd one out when mixed with true spectral members.

Given Data / Assumptions:

• Spectral set includes Violet, Indigo, Blue, Green, Yellow, Orange, Red.
• Pink is a non-spectral, composite/perceptual color rather than a distinct wavelength band.

Concept / Approach:
Test membership in the canonical VIBGYOR set. Items within VIBGYOR are natural rainbow bands; items outside are not. The single non-member is the outlier.

Step-by-Step Solution:
Green → spectral member.Indigo → spectral member.Violet → spectral member.Pink → not a spectral band; perceived from combinations (e.g., desaturated reds with white).

Verification / Alternative check:
Even if “indigo” is sometimes debated in modern pedagogy, both Green and Violet are undisputed spectral colors, and Pink is clearly non-spectral. This maintains a unique outlier.

Why Other Options Are Wrong:

• Green, Indigo, and Violet are recognized rainbow colors.

Common Pitfalls:
Confusing favorite or common paint colors with spectral physics. “Pink” is not a pure wavelength band.

Final Answer:
Pink