PH testing again

I think I did the last PH test about 3 months ago. I did a test today and found my aquarium PH rather high...towards 7.6. How long it has been at this range I do not know but my shrimp's color is pretty solid under such parameter. Was there any co-relations or other factor at play?

Photo taken with and without lighting. Nevertheless, I am quite happy such intense color has been consistent for months. These shrimps are many generations (at least 8th?) from the first batch of Fire Red which I bought from GC 2 years ago.... Since then, I have never added new purchases. Amazing to see their solid red can be sustained for so long.