Quake 1 GOG is too dark and i can't play. Is there any fix?

You'll probably have better luck searching in the Quake forums for patches/troubleshooting:

https://www.gog.com/forum/quake_series#1501078004

or perhaps search a similar forum on Steam.

I assume you have tried the usual basic options, check options in game for a contrast slider (I don't have the game installed so can't remember if it has one), monitor contrast settings and graphics card settings?
You might also want to consider using darkplaces engine re-implementation or even get quake definitive edition off moddb.

Also from memory, but wasn't there an option to adjust gamma?

Also, it's worth mentioning that much of the game is meant to be dark. Maybe it's just a matter of subjective preference?

I'll throw in here: be sure you are using "software settings" in your graphics card options. Don't override the game's settings.

I used quakespasm which has a slider for brightness and gamma.

The Strogg used unqualified non-union electricians to install their lighting systems; of course it's dark!

Did you try turning the light on?

Just use a Light Amulet! Oops, sorry,..Morrowind..

Have You Tried Turning Light Off And On Again ?

There are no Strogg in Quake. The Strogg are from an unrelated game called Quake II

This triggered a very old memory of a story, which was later proved to be false, about a M$ employee and a new user:
http://www.snopes.com/humor/business/wordperfect.asp

Can't believe that was 20 years ago!

Oh my god! What an unforgivable sin I have committed!

I should be scalped, tattooed, hung, and then killed! :O

Er... maybe just get a tattoo and we'll call it even