Thank you very much for your advice. I'll defintely give it a try, but I'll listen to other people, specially if they've tried the mod themselves. I've read in other forums that apparently it depends on which SP you're using, because the first batch was perfect for the CGB mod, not as much as the rest, apparently... Seems more complicated that it was at first.

You put it on LCD. It wouldn't do anything if you put it on light.
For my understanding, there should not be much difference between the films. I know some uses anti glare screen protectors. They are pretty cheap.
And yes, there might be cutting involved.

As a side note: I don't have Color nor have modded one.

Hmmmm. And that is sticked to the LCD or frontlight? (I think LCD : S)
Which type should I get? I have no idea of what I'm loking for really xD It seems that whatever I get, I'll have to cut it to fit the size of the GB.

AR film reduces the glare (what your GBC is probably suffering), and you should be able to get it for example from eBay. And you shouldn't get bubbles if you put it on the clear surface and be very careful.
If you try it and it fails, you should be able to take it off. Somebody please correct me if I'm wrong.

Nope.... They've told me about it here already, but how am I sure it'll do any good? Where can I get it? I've heard that the main problem with that are bubbles when you put it... -.-
If I try it, is it possible to remove it?

Do you have an antireflective film on it?
E: grammatic error

It's dark already, the problem is that it is illuminated, but you can't really see anything on the screen...

Well that sucks monkey balls. Is there maybe some form of filter that you could place over it to make the backlight darker?

Nope, LSDJ is almost invisible there xD

Yikes... in the interim, do any of the different LSDJ color schemes help with your readability issues?

Here's a pic of how it looks like:

In reality it's a bit darker and those weird lines on the right are not happening really.

I'm reviving this thread, again asking for help. I got another SP and retried the mod. This time I was extra careful with the frontlight, and gently put it inside the Game Boy. I also changed the old ribbon connector so I could say the whole frontlight set is new. What is my surprise when I close the CGB and find the same keeps happening! I tried to turn it around and then it's too bright to see (how it should be, from what I've read).
How can it be that it still is too dark to see properly now? Could it be a question of the wiring? I used thin wires from an old RJ-45 cable I think.
I'm quite desperate now XD

So it seems that my only chance is trying with another SP frontlight... and see if it's just that I destroyed mine or something else... Thanks for the help guys!

It's the stuff they use for smartphone screen covers. Some guy that did a GBA frontlight mod recommended using one. I've done the GBC mod with one and it's nice.

Gotta say that from what you say it sounds like it's more than just that, I posted pretty much the same time as APEshit so hadn't read his post before replying...

@Apeshit I do have tried to flip it, but that not might be the thing, since it keeps happening. Sure of that? What a mess I've done then...
@Old Beezy I haven't. What's that? Anyway will that solve my problem? When in the dark, the screen is seen completely black, although lighted...