Why is raw pasta sometimes lighter and sometimes darker?

Milling process: The milling of the flour (fine or coarse) can alter the color. Whole grain flours tend to be darker.

Moisture: The moisture present in the flour at the time of production can affect the color and texture of the pasta.

Storage Conditions: Pasta exposed to light and heat can alter its color over time.

In summary, furosine can be a factor, but there are multiple variables that contribute to the color of raw pasta.