Q.We Bought Our Magnolia Tree Last Year And Had Pink Flowers But This Year They Are Blooming White Flowers And We Wondered Why?
It’s strange how last year was pink and this year it’s white .. besides that, it’s growing beautifully

Certified GKH Gardening Expert
This happens, with many tree and flower species, when light conditions are a little less than ideal. This isn't to say that they won't flower or grow properly, but flower color may be diminished.
To ensure the best color, it is best to give them the best care that you can. These articles will help:
https://www.gardeningknowhow.com/category/ornamental/trees/magnolia

I found this on Wikipedia: There is natural variation within the flower color, which varies from white to rich pink; the hue of pink magnolias also changes from year to year, depending on day and night air temperatures prior to and during flowering.