Light brown oil after winter

I think head gasket (never seen this color and I would never start with that so good you took it out, maybe heat some on a spoon and see if water is present?)

But starting in winter without driving means it does not reach operating temp and so no water was removed from the oil by idling.



Maybe put some of that oil in a jar and see how it separates at room temperature (oil floats on water after a while) and maybe use a bit of new oil with coolant to see if you can replicate?

But condensation in the cold is a lot when looking at months of time. When around 0 degrees celcius more condensation was visible on my fuel-tank and engine.
I keep the fuel tank full to prevent condensation inside.

And when replacing the air-filter my GSXR1000 had to much water in the crankcase breather filter, maybe check the air-filter box?, it has a drain that was dry.
The small

I don't think it can drain back from filter to engine, but maybe...

GSXR1000 :



GSXR1000 2014 air-filter cover inside, squeezed filter in paper:


Top cover of the air-filter, breather GSXR1000 2014



The GSXR1000 2014 airfilter water drain was dry, so that is not really an indication to me:




Add water to oil, still kept going:


The Gixxer forum messes up the attachment pictures, on the original website they can be clicked and zoomed: Suzuki GSX-R 1000 2014 = L4 WVCY/12

Yes, imagine trying to start it with the engine full.

I know nobody who does this and when I bought my 1000 the owner also had a busa in the same storage and I think if this oil problem was normal there would be more info?
Looking at the picture I can not accept this is just and only condensation, the mix is 1:4 water I think, so a full liter of water.

Anyway the storage text from the manual, thanks for mentioning that and it definitely shows there is more (now thinking if I should do this next winter)

STORAGE PROCEDURE AND MOTORCYCLE
CLEANING STORAGE PROCEDURE
If your motorcycle is to be left unused
for an extended period of time, it
needs special servicing requiring
appropriate materials, equipment and
skill. For this reason, Suzuki recommends
that you trust this maintenance
work to your Suzuki dealer. If
you wish to service the machine for
storage yourself, follow the general
guidelines below:
MOTORCYCLE
Clean the entire motorcycle. Place
the motorcycle on the side stand on a
firm, flat surface where it will not fall
over.
FUEL
1. Fill the fuel tank to the top with
fuel mixed with the amount of gasoline
stabilizer recommended by
the stabilizer manufacturer.
2. Run the engine for a few minutes
until the stabilized gasoline fills
the fuel injection system.
ENGINE
1. Pour one tablespoon of motor oil
into each spark plug hole. Reinstall
the spark plugs and crank the
engine a few times.
2. Drain the engine oil thoroughly
and refill the crankcase with fresh
engine oil all the way up to the
filler hole.
3. Cover the air cleaner intake and
the muffler outlet with oily rags to
prevent humidity from entering.
BATTERY
1. Remove the battery from the
motorcycle by referring to the
BATTERY section.
2. Clean the outside of the battery
with a mild soap and remove corrosion
from the terminals and wiring
harness.
3. Store the battery in a room above
freezing.
TIRES
Inflate tires to the normal pressure.
EXTERNAL
• Spray all vinyl and rubber parts
with rubber protectant.
• Spray unpainted surfaces with
rust preventative.
• Coat painted surfaces with car
wax.
MAINTENANCE DURING STORAGE
Once a month, recharge the battery.
The standard charging rate is 1.2A ×
5 to 10 hours.