I don't know about you.. but I am blue green colour blind
Just some thoughts.
I routinely use a
Salifert pH test kit and find the colour difference between say 8.3 and 8.0 pretty easy to read. In an ordinary reef or FOWLR using coral based substrate your pH shouldn't move quickly so I don't think one needs to really worry about the pH that much (famous last words). Just a quick check to see if it's in that ball park is all I really worry about. There shouldn't be anything moving the pH that quickly in the reef. Almost always it is 8.3 and if it's 8.0 I make a note to keep a closer eye on things.
If you run a Ca reactor (or something else that affects pH like regular dosing of kalk etc...) then you want to become more attentive though, more to shifting trends so you can correct them. At that point you may wish to consider a pH probe so that you aren't manually doing tests all the time.