You will find the color of the ears now will be the color of the adult coat. Charlie will be a gorgeous redhead.
Oh man, I love my blondie to death, but Comet is something to be seen! What a rich, gorgeous shade of red.The ear tips are the best indicator, but as PG pointed out, they're not perfect. Our Comet ended up significantly darker than his ears indicated at first, and he has a lot of color contrast in his coat.
As a puppy:
At 18+ months: