Colorful flowers and flowering bushes for shady

I’m on Long Island, NY. House faces north, and my garden in particular gets about 15 seconds of sun each day. As you can see I have some azaleas here, and they do flower but never fill out, in flowers or greenery, especially the ones on the left side. I have those three green bushes to the left side, forget what they’re called, but they bloom these nice white stalks, but even they barely come out anymore and again, even the greenery for them isn’t full. Begonias and impatients do well here, but I’m looking more for perennial flowers or flowering bushes that will just come back and give me some nice color throughout the spring and summer. I see some houses around the area that have it set up where the tulips come out and once those are wilting something else is blooming. I’m hoping for something close to that effect. Total newbie here, so all advice is welcome.