Garmin Forerunner 255 Display Brightness

Hi there, I received my Garmin Forerunner 255 today which I purchased second hand. I can’t tell if it is meant to be like this but the colours on the display seem a little dim. The tutorial videos I have watched, the colours seem more poignant. The brightness is in 100% for during activity and general use. I was wondering if anyone knew if it was meant to be like this or how to fix? Thanks in advance. William