Thanks for the question.  Actually, you asked several questions.

I’m a bit confused.  You said that these were potted hydrangeas but yet you said that they had been planted outside.  So I am a little confused.  Let me respond in a more general manner.

If your hydrangea is currently outside, let it remain there. Trying to maintain an hydrangea as an inside plant is not really feasible.  It is a perennial plant adapted to outside conditions.  Here are my suggestions:

1).  If the plant is currently outside, just leave it there.  If it is currently in a pot, immediately transplant it.

2).  Prune your plant immediately after transplantation.  Depending upon the variety you have, this may or may not impede flowing this spring.

3).  Fertilize with a common garden fertilizer with a composition of 10-10-10.  Water it in well.  I believe that if you do this now (early April 2020), you will soon see buds and new foliage by the end of this month.

4).  While hydrangea do prefer a sunny location, as long as they get at least six hours of direct sunlight per day, they should do fine. 

See the following:

https://www.gardenguides.com/107874-hydrangeas-minnesota.html

Good Luck!!

Thanks for getting back to me. I apologize for not recognizing the twofold nature of your question and the fact that you did provide the varieties of the hydrangeas.

Maintaining a pink color in hydrangea blossoms is easier than trying to develop a blue color.  In both instances, however, it is largely done by adding various things to the soil.  Blue hydrangeas require the presence of aluminum in a rather acidic soil.  Pink hydrangeas require a less acidic soil.  More specifically, do not add aluminum to your soil as this would cause the blossoms to turn blue.  Hydrated lime should be added instead as this will elevate the pH.  A pH of around 6.5 or slightly higher is generally recommended.  You can purchase a pH test kit at most garden centers and this would be a good investment.  In addition to the lime, the 10-10-10 fertilizer I previously mentioned could be used in connection with the lime.

Here are some publications that deal with these and other points:

https://homeguides.sfgate.com/fertilize-pink-hydrangea-65348.html

https://gardentherapy.ca/hydrangea-change-color/

https://homeguides.sfgate.com/keep-hydrangea-flower-colors-73320.html

https://homeguides.sfgate.com/fertilize-pink-hydrangea-65348.html

With respect to your white hydrangeas, you generally can’t change their color so I assume that you will maintain their current blossom color.  Do not use the Holly Tone on your pink hydrangea.  This compound will lower the pH and cause the pink coloration to fade and disappear.  The 4-3-4 Holly tone contains 3% by weight of phosphorus and releases this rather slowly.  The is  for the 4% (first number) of nitrogen it contains.  Generally speaking hydrangeas need a stronger dosages of nitrogen and phosphorus than these in order to get good foliage and flower development.  The 10-10-10 fertilizer would be a better choice for the which hydrangea.

Again, take a look at these sites as they will amplify the points that I’ve made:

https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/fertilizing-hydrangeas.htm

https://gardenhelpful.com/best-fertilizer-for-hydrangeas/

Once again my apologies for my less than direct initial response.

Good Luck!!