Hell yer you have mangaed to stabalise those plants. Yellow leaves look cal/mag a bit and maybe some signs of over watering. Most tomato ferts have good amounts of cal and mag and normally listed on the bottle, think you posted a pic of the ferts earlier.
Anyway it dosen't matter since the yellowing has stopped for now, try and give it a good long think as to why the leaves went yellow and it might of been a few reasons why. Work and refine what you did to make them better, often it is overatering so maybe some perlite or hydroton in the next grow. Now is a crucial time for the plants, you don't want any yellowing to start again, keep that water cycle going as sounds like you are watering spot on! I do see some leaf tip burn which might be from overfertilizing, i am working on a feed feed flush schedule at the moment and seems to be working wonders although i have a pH and ec digital meter. Those liquid pH tester give you a guide but litmus paper would be a lot more accurate and has a bigger colour scale as you have seen, these liquid testers with the bigger colour scale are the accurate ones, yours is rubbish(sorry but it is). I have seem liquid testers that only test in a certain pH range and they are even more accurate, test like from pH6 to pH8 only, if the test show 6 or 8 you need the next test which dose pH 4 to 6 or 8 to 10.
Track your pH pen down as you need it more than ever. One thing i just did wrong recently waas flush some small plants in some small pots and they went bright yellow over night, as far as i can see i have flushed out all the micro and macro nutes as well as the npk, i have added full strength biobizz ferts and maxicrop seaweed and seems to have halted the yellow. Even good growers make mistakes!lol!
Good to see your grow getting well, sometimes its not advice which helps sick plants but talking to others about the problems. Peace and again well done