Hello, I am also in the northeast. Panicle hydrangeas can definitely thrive in 6 hours full hour with no shade in our zones. Just be sure that you select the appropriate size for your space. I love Vanilla Strawberry hydrangeas (and Firelight), but they grow to be 8 ft by 8 ft. If that is too large for your space, consider Bobo, Firelight Titbit, Little Lime Punch, Little Quickfire, etc. I have also had luck with Arborescens hydrangeas in full sun, specifically Invincelle Ruby and Incrediball hydrangeas.

You could also contact with the university with an agricultural school near you for more specific advice. Cornell has one of the top programs in the country.

" I do not want all white, green, or red. "

Sorry but every panicle hydrangea is going to offer colors in this range and often all on the same plant. Not sure what else you expect?

As for sun exposure, this is the most sun and heat tolerant of any hydrangea species. In full sun in hotter climates, it may just require more frequent irrigation to look its best.

The location sounds adequate for a panicle hydrangeas but panicles only bloom in shades of white, pink and green (which you do not like).