How do you manage your red exposure without losing detail and keep the vibrant, true red color?
You have two options, either you do it "in camera" or afterwards in your editing software.
If you choose to do it "in camera" then you have to select the RGB histogram and watch that red channel, make sure it's balanced.
It's an easy method. The luminosity histogram will tell you if the exposure in general is correct, but you won't see the balanced colors.
It may come in handy if you know you have a red subject to shoot.
If you decided not to bother with "in camera" settings, and find your reds have lost detail or look washed out, or too warm, then your editing software will correct the final look of your image. BUT, if there is too much clipping, you will still end up with a loss in detail.
Use the Selective Color command and select the red color, then adjust until the histogram in your software shows the reds to be balanced, or when you are pleased with the final look of it.
Here are three photos I took of a red subject. I decided that exposing the reds wasn't enough of a challenge so I added white china, what was I thinking? :)
The first one was taken outside, natural light, in the shade. The red is just a little too pink for me. Watch that sun, it warms up the reds a lot!
The two following were done in controlled lighting conditions (studio). I find the reds being more true to their original colors. The white china shows a burnt spot where the light hits the rim, but I can live with that. Those shots are basically SOOC, raw to jpeg conversion and resized for web only.
So, go out and shoot those red tulips and poppies! Red is calling you!