Immature blooms look green and turn color after a while. Exposure to sunlight makes them mature faster. Because the wholesaler forced the plant to bloom at this time (normal would be April-May), you ended with his mix of colors. Normally, the greens would be followed by the color that the shrub normally gets (but snce it was forced to bloom at unnatural times, it is hard to know with 100% certainty). After that, in 2-4 weks, you would see other colors.

So it may be a white blooming hydrangea whose blooms started green, changed to white and then turned pink after 2-4 weeks. But you will know for sure the next time that it blooms because you will be there to see it happen.

I remembered afterwards that Lowe's carries the Forever and Ever Series and this shrub could be one of those... like the Together Hydrangea.

Here is a link that might be useful: The Forever and Ever Series

Thank you!