vtgamma(1)

💖 vtgamma — bestie edition 💖

okay so this is the vtgamma man page from section 1 of the Linux console manual. yes it's a real thing, yes it's iconic, and yes we're gonna get through it together 🫶

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✨ NAME ✨

vtgamma — set gamma correction on text terminals 💅

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🌸 SYNOPSIS 🌸

vtgamma [-e] [-r] [-l] <gamma>
vtgamma [-e] [-r] <red gamma> <green gamma> <blue gamma>
vtgamma [-e] [-r]<palette>[<gamma>...]

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💜 DESCRIPTION 💜

vtgamma lets you set the gamma correction on the Linux console. and like, plot twist, it also works on most terminal emulators too ✨

so here's the tea: a good deal of monitors tend to be too dark blue — because the human eye is far less sensitive to blue light. for photographic images that are supposed to look realistic? totally acceptable, no notes. but for blue text, especially dark blue text, it can make stuff genuinely hard to read 😭

vtgamma is also super useful on aged CRT monitors, which tend to rapidly lose the luminance-to-voltage ratio. like, even after just 2-3 years, a typical CRT often needs gamma of as much as 1.6 to resemble a new one. and the author of this here man page (hi Adam) has seen a specimen that needed gamma of 2 2 6 (ie, with a big loss of blue) despite still having a sharp display 💀 iconic honestly

Gamma correction is given as a positive floating-point number, with 1.0 being the default.

You may also select a different palette than the default "vga". A palette may then have a gamma correction applied to it — all options are allowed, no gatekeeping here 👑

This version recognizes the following palettes:

• vga
• gruvbox
• monokai
• ubuntu

To affect the login prompt, it's best to do:

vtgamma 1.6 >>/etc/issue

where 1.6 is the gamma correction you want (but see -p babe).

Without -p, the color profile lasts either until the next time a program resets the terminal. while this is quite a rare thing, it happens, and thus you'll probably want to have the gamma refreshed every time a program exits.

The recommended way is to include vtgamma in PROMPT_COMMAND:

PROMPT_COMMAND='vtgamma 1.6'

although if you don't want to spawn a process every prompt, you may instead edit ~/.bashrc and include the output of vtgamma -e 1.6 in PS1, enclosed between \[ and \]. Unfortunately, this won't work when you switch between terminals using different ways of setting gamma (currently Linux console vs most graphical terminals); Midnight Commander can't cope well with prompts containing such codes either. sad but true 🙈

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🎀 OPTIONS 🎀

• -e, --escape — Escapes the codes in a form suitable for echo -e, C/Perl/... literals, etc. You might want to include this in /etc/issue ✨
• -p, --permanent — On Linux console (VT) only, sets the palette in a way that's permanent until reboot. This uses an ioctl rather than terminal codes, thus can't be captured and written as a string. no strings attached fr fr
• -r, --reverse — Black on white mode. Note that this does what you'd expect only on certain terminals, such as Linux console. On most graphical terminal emulators this affects only "real" black and white but not primary text and background colors. 💀
• -l, --lab, --Lab, --lchab, --LCHab — Uses the LCHab color space (a variant of Lab) instead of RGB, this allows brightening colors above FF0000. Requires the Graphics::ColorObject library (on Debian, install libgraphics-colorobject-perl). 🧚

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🦋 SEE ALSO 🦋

xgamma(1)

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👑 AUTHOR 👑

Both the program and this man page are the fault of Adam Borowski. Both of them are in the Public Domain, or the closest approximation allowed by law. slay, honestly.

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and that's a wrap bestie 💖 this page came to you from the Debian crew, dated 2006-07-10, for vtgamma(1) — go forth and correct those gammas, you absolute main character 🌈✨