Re: What is the actual 50% gray hex?
Posted: Sat May 31, 2025 8:35 pm
reposting to Tawbie, I follow this. And that is for this, that I talked about cga standard (which is different to True colors ).
00h = black
55h = dark gray
AAh = gray
FFh = white
So, in this way, a 50% gray is half from 0AAh which is equal to 055h (dark gray).
Note for AZJIO :Here, we can see the gray true color inverting stays near a gray true color, but a gray cga color becomes a dark gray.
You could note that this 255/3 coefficient has a good ratio to find the brown colour : $AA5500 (rgb order) (CGA) compressable to %10 01 00 (6 bits rgb). Technically, the CGA displayer received the colours of each pixel bit per bit and that broke the eyes. If we cut the color code, this is presented like this : % iR iG iB. i is the intensity. There was also 4 wires between the graphic card and the monitor. This standard was named RGBI, and this really destroyed the eyes. Today, it just stays these 3 * 2 bits which compress the color datas of a pixel. And our displays are very speed. No black line between two blinding pixels, no screen horizontal lines which twinkles 15 times per seconds, and no scrolling which breaks the pictures of a graphic animation. We are very lucky today.
I think if the true colors are not linear, it is because the hardware must adapt the picture to the human eyes...
00h = black
55h = dark gray
AAh = gray
FFh = white
So, in this way, a 50% gray is half from 0AAh which is equal to 055h (dark gray).

Note for AZJIO :
Code: Select all
dim x(7)
x(0) = $FFFFFF - $808080 ; is equal to...
x(1) = #White - $808080 ; which is also equal to...
x(2) = #White ! $808080
x(3) = #White ! $7F7F7F
x(4) = $000000
x(5) = $555555
x(6) = $AAAAAA
x(7) = $FFFFFF
For i = 0 To 7
Debug Hex(x(i) ! $White)
Next
You could note that this 255/3 coefficient has a good ratio to find the brown colour : $AA5500 (rgb order) (CGA) compressable to %10 01 00 (6 bits rgb). Technically, the CGA displayer received the colours of each pixel bit per bit and that broke the eyes. If we cut the color code, this is presented like this : % iR iG iB. i is the intensity. There was also 4 wires between the graphic card and the monitor. This standard was named RGBI, and this really destroyed the eyes. Today, it just stays these 3 * 2 bits which compress the color datas of a pixel. And our displays are very speed. No black line between two blinding pixels, no screen horizontal lines which twinkles 15 times per seconds, and no scrolling which breaks the pictures of a graphic animation. We are very lucky today.
I think if the true colors are not linear, it is because the hardware must adapt the picture to the human eyes...