My guess would be black knight or president. Check out some photos and see if they match the one you saw.

India Prince is a crimson red, no orange, very refined small flower, about 3 1/2 feet tall, green leaves with a thin crimson edge.

Lisa

I agree with all 3 choices for vivid red color.The India Prince is especially blood-red in color, and spikey blooms instead of showy.
-stephen

some good choices:

The President
Firebird
Boca Blue

I believe you can order all from karcheskycanna.com
good luck!

Boca Joe

Thanks, all. Boca Blue is the closest to what I remember.

I have a nice canna indica, the color is very good but Debbie doesn't like the flower form.