Question

Color is a result of the absorption and reflection of light. A shirt appears a color because it reflects that color of light. A shirt appears black when it absorbs all wavelengths of light.

Why does a shirt appear white outside on a sunny day?

The light is transmitted through the shirt, so no color appears.
The shirt absorbs the sunlight, so it appears white.
All the light is reflected, so the shirt appears white.
The sunlight refracts when it hits the shirt, so the shirt appears white.

Answer 1

All the light is reflected, so the shirt appears white.

Explanation: Sunlight contains all visible wavelengths. A white shirt reflects most wavelengths roughly equally (rather than absorbing them), so you perceive white.