There should be a unique building used to convert rainbow ore (and the ore itself could be renamed to sound a bit more thematic), which could be placed just after logistic or chemical science so you can't immediately use it. Being able to stockpile oil at the start of the game makes it feel a tad unbalanced imo, and being able to use it from the start of the game kinda nullifies the point - you can easily double up on resources early on and start to stockpile basic ones you'll need later.

If you have space age, there is an option to allow biochambers to be used for conversion. I do not want to add a building that is only used for conversion, as I believe it adds unnecessary clutter to the game. I'd like to keep this mod relatively simple. The ore name is a bit silly, but it's ended up growing on me so I'm unlikely to change it.

Stockpiling oil seems like a very silly idea considering oil is normally infinite and rainbow ore isn't. And doubling up on resources is kind of the point? If you don't have enough iron, then you can turn the rainbow ore into more iron. If you started with 3 massive iron patches nearby, maybe you start treating the rainbow ore as copper instead.

Lastly, it needs to be available from the start of the game so that rainbow-only runs are possible. It's probably the better way of using this mod imo, making all of the base materials from one type of ore.

(Also I'm aware that I've basically just said no to all your suggestions. Please do explain your side more if you don't agree with my reasoning, as I'm open to change stuff given good reason.) Perhaps some sort of conversion ratio option might balance it for your game? 2 ore to 1 iron options to prevent ease of stockpiling? I can see myself adding something like that if it's wanted.

I don't have space age (and i'm not really interested in buying it), but alright then. Suggestions get rejected all the time lol, so i don't mind (i only take issue with it if the dev is an asshole about it. Never gonna understand why some people do that lol).

I did notice the option though, and i think the Foundry would be a more fitting machine (since it's meant for metals & such), but i suppose the innate productivity might conflict a bit. Would be good to add options for both though, in addition to a setting that removes the default recipes and forces players to use whichever crafting machine they select.

Options to customize the ratios would be nice too. Making them all a list in the settings (with any custom modded ores the user adds being added to said list) would be noice.

Oil fields tend not to spawn in the starting area, and I'm lazy lol - so i'd just use the ore by default. That's the only reason i listed it.

would also be nice if there were config options to add fluid requirements to various ores defined in the whitelist.