Rainbow colours (VIBGYOR) — arrange the following in spectral order: 1. Indigo, 2. Red, 3. Violet, 4. Blue, 5. Green, 6. Yellow, 7. Orange.

Introduction / Context:
Reordering the visible spectrum by VIBGYOR is a common GK check. Given differently numbered colours, you must translate the mnemonic to the provided indices.

Given Data / Assumptions:

• Mapping: V(3), I(1), B(4), G(5), Y(6), O(7), R(2).
• Order sought: V → I → B → G → Y → O → R.

Concept / Approach:
Write VIBGYOR using the provided index mapping, then transcribe the index sequence directly.

Step-by-Step Solution:

Verification / Alternative check:
Confirms standard spectrum order and consistent mapping to indices.

Why Other Options Are Wrong:
They misplace one or more colours relative to the standard spectrum.

Common Pitfalls:
Interchanging orange and red at the end.

Final Answer:
3, 1, 4, 5, 6, 7, 2