For pH, I would like to show its value in RED if it drops below 7.2 or if it goes above 7.6 (in other words, there is a range at which it’s optimal and if it’s not, I want the value in red). Same with the sanitation or salinity levels. How is that achieved?
Go here and check for examples.
Then go here to discuss any card-mod stuff. Also examples may be found in the end of the 1st post (a link to examples is provided there).