I'd like to make my text editors display like the old skool white-on-green VDUs of yore that I can just about remember from my childhood. I have this idea they might be easier on my old eyes.

I was wondering if there was standard dark green used on these and, if so, what the RGB or Hex values for it might be?

5 Answers

DaveBoltman's answer is very remarkable and useful. However, the phosphors' wavelengths in Wikipedia are not exact. There are other references and Google books giving slightly different values. For instance, P1 w/l is 525, not 528 nm:

Anyway, I remember what colors those phosphors displayed (including the amber phosphors), so I am nearly sure of these RGB and Hex values:

I suppose that Apple //c and Apple /// monitors used the P24 GE phosphor, because they had its hue. And the background of the old monochrome CRTs usually was lighter than pure black, see this photo:

For better eye comfort, I suggest that the OP use any of those greens with that background. In the dark, the old-fashioned green on dark gray looks better than the present black on white.

3

Inspired by the above (incomplete) answers:

1. Almost all the "'old fashioned' green screen computer displays/VDUs" used the P1 phosphor (see wikipedia reference)

2. The P1 phosphor produces a peak wavelength (a.k.a. colour in human terms) of 528 nm (reference)

3. Converting colour from a wavelength to RGB values (in the commonly used byte format of 0 to 255) using formulae here, gives: Red=65 Green=255 Blue=0, or #41FF00 in hexadecimal. (see this convertor).

4. This does not take brightness into account. (to adjust the brightness the RBG value would need to be converted to HSV, have the V component adjusted up or down, then converted back to RGB to satisfy the OP).

From Wikipedia you can find a wavelength of this phosphor and RGB conversion formulas can be found easily from internet.

1

• There wasn't a standard color.
• Brightness is part of color and was usually changeable by turning a knob.
• Colors change as the phosphor ages.
• You could order VDUs with amber and other color phosphors.
• Some makers claimed amber was better for eyes.
• The ones I used were mostly green on black (not white on green)
• RGB values probably depend on calibration of your display.

4

Try RGB color code:

R:36
G:204
B:68

For a result like this:

1

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