No, I don't know what the ratio would be.
I would probably just provide it separately and see how much the hens want to eat. For peppers, the easiest way I know is to use fresh peppers in your own food, and toss the trimmings in the chicken run

For alfalfa hay, it would be easy to put some in the pen and let the hens scratch it around eating bits. For chili powder or marigolds, maybe put some in a dish with some chicken food and water to make a wet mush? Chickens are usually happy to gobble up a dish like that, and you could just measure in a given amount per day, instead of trying to incorporate it into their whole food supply.
What type of feed do you normally give the chickens? It is hard to add anything to pellets or whole grains, because powdery bits fall off and get ignored. It is much easier to mix things into crumbled or finely ground feed.
I know that egg yolks take a while to form, so no matter what you try, it will take some amount of time before you see results.
One time I was slicing hard boiled eggs and got a surprise: darker and lighter areas within the yolks! I suspect it was because we were eating peppers in clumps, so the chickens got a lot on some days and not on other days.