Preface:

If you are here, it is likely because you somehow found this obscure guide in the middle of nowhere and like using [Chroma]. Well I have built just the tank for you, with extremely high ability strength and a lot of survivability, this frame is the perfect frame to bring into the harder content offered in the game. Just glance over the headers and see if any of the info applies to your needs. Or completely ignore it, and do what you want, but don't complain to me.

Helminth:

Replace effigy or spectral scream with gloom for a more consistent source of healing than elemental armor when needed.

This can pretty much get you through most content, but keep in mind that the range is a bit unimpressive, but it gets the job done. Especially for melee.

[Chroma] Element:

I use fire element [Chroma] for the healing. The other option I could see is ice [Chroma], but I feel that fire is overall better survivability. But really that is probably a personal preference for having a huge health number (as well as the healing it does on reapplication).

Gameplay:

Just keep up elemental ward and vex armor, and enjoy dealing ridiculous weapon damage while taking next to no damage in most content. Make sure you avoid letting vex armor expire, as you then have to rebuild the percentages by taking damage again.

Speaking of taking damage, you are likely to struggle to utilize vex armor in lower level content, as usually things die so quickly you can't take enough damage to benefit. While the lower damage numbers feel lame, this is okay, as technically the only time you ever actually NEED the damage is if you are against enemies that can actually hurt you anyway. That is what makes [Chroma Prime] great for steel path and such, but boring for most low level content, especially in co op.

Why not [Primed Flow]?

We use normal [Flow] because [Chroma] already has a lot of energy at his disposal so he doesn't need as much as the average frame, and we can't use [Primed Flow] without another umbra forma, so in a sense we would be spending an umbra forma only for more maximum energy, which isn't very worthwhile and is arguably not even a gain.

Other notes:

Since this build is a bit energy expensive, it is a good idea to either use zenurik, or an energy [Regen] [Grimoire], as relying on drops alone is not likely to be easy to maintain.

Another thing you can do for even more ability strength is replace [Flow] with [Augur Secrets]. This gives you a lower energy pool, so you really need to be on top of energy regeneration (I would even use both zenurik and [Grimoire] together for best results) but more ability strength, in case you want even more ridiculously high damage numbers. In my opinion the exchange isn't worth it, as we get plenty of damage already, but it is an option.