We received the following question by e-mail.

I please was curious to ask about Cool Green fluorescent lamps -- from what I understand, they are supposed to have been popular in factories where drawing plans was once done by hand, since the color given off is supposedly better for the eyes when doing such detailed work.  Is this true, and would these lamps have been used in schools or other specialized settings?

Additionally, when was the Cool Green type of fluorescent tube first introduced (and are they still used anyplace today)?

When I was working in the Forest Park, Georgia ( Atlanta area) directory assistance office, it was lit with cool green. It was a very pleasant light to have to do work under. 

In my high school years, we had about a dozen cool green lamps scattered throughout the building. My best guess is that it was a commercial sample but other than looking directly at the fixtures you couldn't tell that they were there. They made a good effect in the louvred fixtures, though.

I am wondering also if they are still made although I would imagine that they would be relatively expensive.

Interesting discussion! 

I don't think I've ever seen such green tubes in general lighting.
How would you describe the tint? Pure green? white + green? greenish white? Lemon, grass green? I'm curious and I hardly imagine an office being lit by green light.

I've never seen a whole room full, but only a few scattered around. It's been at least 15 years since then so I am relying on my memory. If I remember correctly, the colour was a beautiful green with a very slight bluish tint. It certainly made a very interesting effect in the louvred fittings.

On a related matter, I remember my grandmother had a makeup mirror that was lit with two daylight F8W lamps. There was a sliding lever that changed filters over the lamps. You could, in addition to daylight setting of no filter, choose among evening with a pinkish purplish filter and office with a green filter. I guess it was meant to be used by someone who worked in a cool green lit office.

I had my room lit with only cool greens before. The color is like a minty green.

Thanks, that's interesting!

Cool Green seems to be similar to a Mercury Vapor lamp's light. I love it.  I have three F40/Cool Greens and put them in a 3 tube fixture with all the other lights turned off. It really is a pleasing color.

These colored fluorescent tubes were used a lot on amusement park rides, and still used today on older rides. It seems like the trend now is RGB LEDs.

I think the last time I ever saw a cool green lamp in use was in the mid-'70s.  I believe it was in either an office or school setting, F40s with louvered ceiling fixtures. The effect is unique - I have not seen anything like it since. It is kind of like mercury vapor. When I envision it in my mind, it feels like the 1960s, like a newspaper production room or something, with metal desks, black asbestos tile floors, and black rotary dial phones.

I think the green was intended to reduce eye strain, along the same lines as using green tinted paper for steno and legal pads and also yellow chalk on blackboards.

I want a cool green fluorescent, mint green is one of my favorite colours

I'm also looking into getting some as well.  They're similarly hard to find as Chroma 75, another color I was glad to finally find.  I find Chroma 75 (7500K, 92 CRI) is much nicer than Daylight Deluxe.

Yeah, they aren't too common but F40s can be ordered.  Semperlite and lightbulbs.com both have them.

5 bucks for a cool green lamp??? Have you used these before Patrick? If so are they any good?

If they are ima save that link...

Yes, I have two from Semperlite and at least at the time they were distributing Sylvania lamps.