Q.Camellia Changing Color
I was given a healthy, young camellia plant three winters ago. Its blossoms were white, sometimes tinged with pink. Its second spring after planting, it produced no blooms (lack of watering on my part, the previous summer). This winter it bore lots and lots of fat, healthy buds. But they are now blooming pink! Completely, all the way pink. No more white flowers like in the beginning. What happened? Is it possible to change the blossom color back to white by altering the soil composition?

Certified GKH Gardening Expert
It probably reverted back to a selection in its genetics, since it had two colors previously. If that is the case, it probably won't revert back. It also could be a "sport," which is a genetic mutation. That is how lots of new cultivars are discovered. Those are usually not the whole shrub but a branch or two.
The stress of the low water the previous winter could have initiated the change. Temperature, nutrition, and pH also can affect flower color. Camelias do prefer acidic soil (5.0 to 6.5) and, they do perform poorly in alkaline soil. You can test your soil and see if it is more alkaline, and if it is, it wouldn't hurt to lower the pH and see if it affects your plant color.
https://edis.ifas.ufl.edu/ep002
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/raise-acid-level-soil.htm
https://www.gardeningknowhow.com/ornamental/flowers/camellia/camellia-fertilizer-info.htm
https://www.gardeningknowhow.com/ornamental/flowers/camellia/caring-for-camellias.htm