Hello, echinaceamaniac. It requires similar care as any other hydrangea mophead. Well draining, acidic soil; amend the soil if it is alkaline. The blooms will change color based on soil acidity and the availability of aluminum. Protect it from the sun in the lower half of the country (give it shade by 11am or 12pm); protect it during the worst part of the afternoon in the northern half of the country. Give it about 3-4" of mulch all year around. Provide constant soil moisture as best as you can (water the soil, not the leaves, early in the mornings). You can fertilize (compost, composted manure, cotton seed meal) in June in the northern half of the country starting on year #2; fertilize in May & June in the lower half of the country. It is unknown at this stage how winter hardy it really is. Its website claims Zone 5 but talks a lot about winter protecting so it is hard to tell for sure. There have been only exploratory posts similar to yours here but no one has reported problems. It may simple be another "Lady in Red" type of hydrangea. Both are from the Netherlands.

Here is a link that might be useful: Abracadabra Hydrangea

Most Hydrangea macrophyllas are fully root hardy to zone 5. It is the nascent flower buds that are damaged by winter cold (or late spring freezes) so all should receive some sort of winter protection in zones below 7 to preserve flowering. I'd even include the remontant or new wood blooming types like ES and its cohorts in this advice. While several of these have increased root hardiness (Z4) and will still flower from new growth if left unprotected, the plants typically will act as herbaceous perennials and die to the ground each season, thereby never really assuming 'shrub' stature and being late to produce flowers......by no means "endlessly" through the summer :-)