Lemon Boy is a waste of space.

Try Jumbo Jim Orange, it's extremely tasty, I won a tomato contest with it.

https://www.mariannasheirloomseeds.com/heirloom-seeds-catalog/mariseeds-heirloom-tomato-seeds/yellow-orange-tomatoes/jumbo-jim-orange-detail.html

I think I`d like to try JumbpJim and maybe a Dr. Wyche`s Yellow too, next year! I live in Reno, not that far from Sacramento, but of course, the weather is different. Thanks!

I'm in Michigan, so my weather is much, much different than yours. My daughter likes the yellow/orange tomatoes very much and her favorite is Golden Jubilee. I prefer Great White, although it's not really yellow, it's a creamy white beef steak type tomato. Golden Jubilee is a prolific tomato here, though.

Annie

You might try Sungold F1, White Queen, and Persimmon. They're all good. White Queen is white, though (kind of yellow). Some I haven't evaluated that might be good include Blush, Isis Candy, Blondkopfchen, Aunt Gertie's Gold, Jim Dandy, Galinas, Golden Queen, KBX, Kellogg's Breakfast, and White Tomesol (also white). Some of those I've partially evaluated.

I've tried Kellogg's Beefsteak, which had great flavor; I'm not sure if that was supposed to be Kellogg's Breakfast.

Those perhaps aren't all equally heat-tolerant, though. They don't all seem to be heat-tolerant.

I have never successfully grown a white tomato in Sacramento, they don't seem to like the heat.
In addition to Jumbo Jim, I also like Orange Russian 117 and Orange Strawberry. I think they are tastier than Kellogg's Breakfast and Persimmon, although of course all of them beat Lemon Boy!
I racked my brain for light yellows, but the only heat tolerant one I really like is Yellow Peach, but it does not taste very "tomatoe-y", it's very fruity and so might put some people off. I like it for smoothies.
Carla in Sac