Strawberry Vanilla is not pink all the time. Like other paniculatas, it starts out a creamy white and then ages to a pink later in the season.

If you want a hydrangea that stays pink from bud opening onwards, you need to look at Hydrangea macrophylla or bigleaf hydrangea (like your blue flowered ones). While these are often influenced by soil chemistry as to their flower colors, there are some pinks that are relatively stable in their coloration and are not greatly influenced by soil chemistry - Glowing Embers. Pink 'n Pretty, Pia (aka Pink Elf), Summer Crush. Or you can apply limestone around the plantings to encourage a pinker color in a typically blue flowered plant.

You can't really change the intensity of the flower color....a light blue hydrangea will never turn a darker blue. If you want a deeply blue flowered one, you need to select for that attribute.

There are some Hydrangea paniculata like SV that turn from white to pink earlier in the season and some that keep white for a longer time period. However in zone 7, they often don’t turn a nice pink because many like cool temperatures to get good pink color. So where I am in central NH, Quickfire, Little Quickfire, Zinfindoll, among others turn a rich pink, but they might not where you are, depending on your location. Be aware that SV tends to arch or even flop due to slim branches and heavy flower heads. Here it only is pink for about 6 weeks to a month as it develops color mid season.

I am also in 7a and my Vanilla Strawberry hydrangeas have developed beautiful pink color every year thus far. However, not all 7as are created equal, so it really depends on your specific location. Also, as gardengal and nhbabs noted, it is not pink all the time. Go with a pink mophead (macrophylla) hydrangea if you want a pure consistent pink.

How about https://www.google.com/search?ei=ipdFXs7eC8Xr5gK03byYAw&q=firelight+hydrangea&oq=firelight+hy&gs_l=psy-ab.1.0.0l4j0i22i30l6.3250.5372..6678...0.2..0.81.222.3......0....1..gws-wiz.......0i71j0i67.IDjoE9S6MFE

I think I would stick with paniculatas as they are easy to grow and hardy in a transitional zone like 7A.

Although they start out white, most turn to a shade of pink in late season. Here is a quick reference for you to look over:

http://mahoneysgarden.com/the-wondrous-world-of-hydrangea-paniculata/

Regards,

Will