Hydrangeas are bountiful, lush, breathtaking flowers and come in subtle shades of blue such as light, powder blue, and sky blue. The shade of blue achieved is determined by the alkalinity of the soil. Blue hydrangea conveys a deep understanding and strong feeling of love and adoration when given as a gift. Hydrangea also symbolizes grace, beauty, and prosperity. This bloom works great with most other florals as it complements other shapes and colors well, and it makes for a stunning arrangement on its own, too.