Don't think you'll find purple or blue but something close to a pink would be cup and saucer magnolia or cherry but if exposed to wind blooms will not last long. Since I went to Farmingdale decades ago see if they have a plant listing because they would have weeping or dwarf varieties. SUAT&I when I went so only God knows what they renamed it. They have a great arboretum at Stony Brook or used to. There are some great dwarf Japanese maples and although they bloom they are inconspicuos but their leaf textures are amazing as are leaf colors and they last throughout the season. I kind of collect them, with no place to show them, but I bought a tri-color, red, white and green leaved from Jim Herter on e-Bay, can't wait for it to mature, he is in NC. I know the nurseries on L.I. should have a slew of them, they did when I was there but of course many now are developments. When you live in cold zones you must alter your focus unless you want disappointment to follow. My sister is in Toms River and was surprised when I saw crepes being sold and she wanted one so I bought it but didn't get through the winter.