That's the point, it's randomised (except for the first and last blocks) so it shows how perceptive you are colour-wise. Maybe you're actually struggling with colour and should see a specialist if you can't really differentiate them (after ensuring that the screen is not the one having a fault).
What's the point in seeing a specialist if you suspect your color vision is crap? As far as I know, the vast majority is genetics and there's no treatments.