I have black shade cloth on the outside of my greenhouse (I don't grow tomatoes - it's just for cooling) and it has worked well enough. I think you are on the right track heat wise to use a lighter color. I would guess that overhead shade would be best, meaning that morning and late afternoon sun is not blocked. A shade cloth which is several feet above the plants will insure you don't trap a lot of heat. The shade house structures I remember working in at the botanical garden are 8' high or more.

Those trellis poles go up to 7' so I will drape over those and keep the plants down to 5.5'. Since I switched to drip, I have much fewer disease problems, so I'm not too concerned on that front.

Any thoughts on either color (including aluminet) or light filtering?

The black stuff does radiate some heat but as long as there is a breeze or a few feet between the cloth and the plant it doesn't seem that bad. You can definitely tell if you hold your hand a couple of inches away though.

I would probably try the aluminet if I didn't already have a bunch of shade cloth.

Just ordered some aluminet from IGC at 50% for the tomatoes and some 40% for everything else. This is all in the front yard, so if the aluminet is too reflective and annoying to neighbors, I'm going to send it back for the white stuff

I can't wait to see pics of your Star Trek veggie garden.

Home Depot has a shade cloth in beige by the roll. We used it for the kids play structure.

Your tomatoes look beautiful! There are just two of us, and we heard tomatoes won't grow here. Too hot. So we have one jalapeno pepper and one tomato in partial shade. They get about 2 hours of partial sun in the morning and mid day. Both are growing well. The pepper has many peppers, but the tomato hasn't blossomed yet. She is too young. I read in the Garden Experiments forum that many people successfully grow all kinds of things in the shade where it's too hot otherwise.