In infrared. Titan basically looks like a brownish grey blob to the naked eye due to its incredibly dense atmosphere.
Knowing it’s just color shifted makes me wonder if that white band in the upper right that looks like a reflection off the atmosphere is actually a reflection off the atmosphere. And also what method of color shifting was used. Are the colors representative of anything or did they just pick what made for the best photo?
They basically remap wavelengths, so yes, absolutely those would be representative of real features, either in the atmosphere or on the ground.
That said, absolutely, sometimes there’s a bit of artistic license in how the wavelengths are mapped.
Edit: the space.com article on the image describes some of the physical features depicted:
https://www.space.com/james-webb-space-telescope-saturn-moon-titan