I’m not sure how the wood is finished, oil?, wax? but it seems the surface refresh is long overdue as it’s changing shade upon any touch or cleaning.
I guess I should at least apply some protective wax or something, but I’m not sure what’s safe to use.
Oil baby oil. If it soaks in, good. If it doesnt then you probably have a varnish coat. Sand, then oil or revarnish. Always use water sparingly when cleaning the floor
Thé most important thing do know is are you renting or do you own?
If it’s the former then ask the rental agency or landlord what sort of floor it is and how best to treat it.
If you own then do as kiwi Steve says and try a drop of oil to see if is absorbed. Do it in a corner somewhere that won’t be visible.
yuck, so it’s normal for this type of coating, what a stupid idea especially for the kitchen floor
it absorbs any liquid
varnish it
Rule 1. Do not spill liquids on a wood floor, especially body fluids
Rule2. Use a dust pan and brush or if you are lazy a vacuum cleaner to remove both solids and liquids.
Wet washing is best done by a professional, which you clearly are not.
You mean by a maid/cleaning lady? I just got the “this is Switzerland” kind of vibe…funny thing btw - I know someone who recently moved here and was convinced everyone has a cleaning lady in Switzerland!! 
The floor tiles in our basement were grubby with ingrained dirt when we moved in - despite having been cleaned by a “professional” company.
We complained and they came back and cleaned them again but they said they couldn’t get them clean.
I managed with household cleaning products and a little bit of effort.
I’ve been just shocked as this is the first time I’m having such floor. I guess I’m not very careful, I always drop some water on the floor as I never care to use towel, especially when I’m in the kitchen and use water often anyway
then of course I use vacuum cleaner, but the stains needs to be cleaned with a wet mop. This apartment turned my life upside down, like living in a NASA laboratory or something
A Küchenteppich or Küchenläufer would help
https://www.ikea.com/ch/en/p/gangstig-kitchen-mat-flatwoven-green-off-white-10578147/
I never understood why people use such a thing, I think it’s discusting. On the other hand I never had wooden floor in the kitchen. While I do have an open ktichen-livingroom, the 2.5m where the cooking happens is tiles.
So you got a point. Still discusting though, no? Or are they washable in the machine? If so they’re too flimsy and not safe, are they.
I was serious about a dust-pan and brush for small liquid spills. Much more practical than a mop or towels. I have a Bissell electric mop which ifs great for wet-cleaning and for vacuuming up larger liquid spills.
I personally wouldn’t use one myself, but then again, i hardly ever spill anything, and if i do, it wouldn’t be of a magnitude to destroy the kitchen floor.
yeah, I’ve already bought some waterproof but washable rug in Landi
If the floor is absorbing liquids as easily as you say it is I think there is an issue with it. It probably needs treating with either wax or varnish to give it some protection.
An untreated wooden floor would be an odd choice for a kitchen.
If you’re renting contact the landlord or agency about it, if you own get a wood floor specialist in to have a look at it.
Can you cover it with a kitchen mat that is water-proof/oil-proof? Some sort of vinyl kitchen rug? At least in the areas that are more problematic.
