Lego and sunlight

[fred67]

Well... what are you blocking? If you have fluorescent lights, I'd suggest replacing them with LED. If it's light from windows, then there's something like this you can get for the windows.

Depending on your glass display case, you could put that coating on it, as well, but it wouldn't work for unusual (like dome) shapes.

Some display cases already have UV protection.

Edited February 25, 2015 by fred67

[Khaled Yousef]

Thanks fred67, that’s it, and I believe any LEGO room should have those UV blocking sheets on the windows; this might be the best solution to protect displayed items from indirect UV, and protect bricks during building too. And if the room is protected you won't need expensive UV-proof cases for individual items.

[LEGO Historian]

I've had a bunch of yellowed classic windows in mint that I put in a bright sunny window sill... and within a month they were white again.

On the otherhand, I've had white parts (mint) stored in my basement in twilight darkness for over 20 years... and they still yellowed.

Other than white parts, all my other 30 year old LEGO parts have fared quite well without discoloration.

And any comparison of older versus newer LEGO colors is not a fair comparison. Newer parts are generally brighter in color... likely some changes in the coloration process. Newer red bricks for example are made of a brighter red plastic than older ones.