Doors and frames from different shops?

Hello everyone,
once again a question from me.
It's about us wanting to replace the doors in our prefabricated house. However, the wall thickness is only about 6.5 cm, making it difficult to find suitable door frames. I have a flooring installer in my circle of acquaintances who also installs doors. Unfortunately, the local manufacturer he works with does not offer door frames in this width. However, I found some online. Since I would like to source the doors themselves through my acquaintance, my question is whether you can simply buy the frames from another shop and then get the doors locally?!? They must be standardized somehow, right? I made sure that the color tone would be the same (frame: CPL RAL 9016, door according to catalog: painted RAL 9016).
Can you just combine them like this or what else should be considered? Then I would order the frames online and have my acquaintance provide the doors.
Thanks!

It would be lucky if the colors match, It already starts with different substrates. Buy everything from one source and that's it.

I would like to, but the local dealer does not offer the thin door frame. Hence my consideration. But if it's a problem, I will probably get everything online. Let's hope everything works out that way. Thank you

Better to have everything from one source. Don’t rely on RAL. The fine print usually says, "similar to RAL XXXX." Moreover, the shade can be identical, but due to different substrates, textures, materials, there are still differences – as tom already wrote. That won’t work.

Get sample pieces of the frame and door leaf to hold them against each other.

I’m also not pleading for the first time here to start a construction project by procuring a RAL color fan. That’s a well-invested ~50€ that can be passed on later through classifieds.

Hm ok. Then I will probably buy all doors and frames online. I have one more question. I measured the wall thickness again today, it is 65mm. According to the homepage, there are now two options for frames: 50 (50-65mm) 70 (65-85mm) Which one is more sensible for more stability? Frame 50 or 70? Theoretically, I can choose because both fit?!?

Hm Ok. Then I guess I will buy all the doors and frames online.

That is the better decision!

What is more sensible here for more stability? Frame 50 or 70? Theoretically, I can choose because both fit?!?

I would take the larger one, since your wall is surely not exactly 65 over the entire height. The connection to the wallpaper can then be nicely concealed with acrylic.