His boots are most definitely yellow. Ask him to sing his song to you. He'll tell you.

The latest Lord of the Rings Online Lorebook entry examines the elusive Tom Bombadil, who aides the hobbits on their way through the Old Forest.

This verse describes the surface appearance of the strange entity known as Bombadil. He seems a jovial (if not somewhat absurd) fellow, skipping and singing through the treacherous Old Forest at the Bounds of Buckland; but beneath the surface is hidden a Power that few, even the Wise, can comprehend. He is old beyond the count of years – indeed, the Elves once called him Iarwain Ben-adar, Oldest and Fatherless – and once leapt upon the hilltops across the wide lands of Middle-earth. Now, though, he has settled in the Old Forest with his wife Goldberry the River-daughter, and set for himself unseen bounds which he no longer crosses.

Read the entry at the LoTRO Lorebook.