Hello all,

Tomato production is at least three weeks early this year, and so are the unidentified diseases!

Same disease footprint here Salaam. I believe it is one of the mildews, and comes with the hot and humid weather any time in the season.
If you look under the leaf that is turning purple, you should see light brownish spores. At least, that's what I think I'm seeing here.
Wish I could tell you what to do about it, but all I am doing is prune it out so it doesn't drop spores.

My two antho varieties are doing this, too. The others are ok.



AND THIS ! ?

Here are some purple pics from mine fwiw to compare.
Purple streaks turn up in the upper canopy and directly related to the flow of air through greenhouse vents. Any exterior leaf surface can be affected whether old or new growth.
Underside is a shallow pile of spores. I didn't keep any long enough to see exactly what the late stages look like.
This swathe of purple appeared in one day. This one has some yellowing too, and you can see at the tips what I believe to be mites biting. Pretty sure it is some biting thing. Underside looks pinky-brown and ready to carpet bomb the fruit! Red alert!
Unfortunately in past experience, this affliction continues to blow in through the vents as long as it's both hot and humid. On times I have removed one layer of leaves, then another, then by golly they are close to leafless if the weather holds sway. But they are fine if they can survive as long as it takes, and get normal healthy leaves again as long as it's either too cold or too dry for this thing.
I'm thinking it's some kind of downy mildew, internet pics vary a lot so IDK for sure.