Alternatives to Pastel
Generate, convert and manipulate colors from the command line. The listings below can replace it for an important use case. Each note says what changes if you switch.
The original
Pastel
Generate, convert and manipulate colors from the command line.
Replacements
Listings that take over the same core job as Pastel.
Color Hexa
A web color encyclopedia with conversions, schemes, shades and colorblind simulation for any color.
Color Hexa moves color conversion, schemes and shades to a free website with colorblind simulation, but it is not open source.
HTML Color Codes
A web color picker and reference for Hex, RGB, HSL and OKLCH color codes.
HTML Color Codes is a web picker converting Hex, RGB, HSL and OKLCH with image extraction, replacing the terminal with a graphical page.
Gpick
An open-source desktop color picker and palette editor written in C++ with the GTK toolkit.
Gpick is an open-source graphical desktop picker and palette editor for Windows and Linux instead of a command-line tool.
OKLCH Color Picker
A web color picker and converter for the OKLCH color space with P3 and Rec2020 views.
OKLCH Color Picker is an open-source web converter focused on OKLCH with gamut views, working on one color at a time in a browser.
Also worth comparing
These listings name Pastel as their own alternative, so the relationship runs both ways.
Encycolorpedia
Color reference website with hex codes, a color picker, color space conversions and paint matching.
Pastel moves color lookup and conversion to an open-source command-line tool for Windows, macOS and Linux, without paint matching or a web directory.
Eyedropper
A GNOME app for picking colors from the screen and viewing them in many color formats.
Pastel is an open-source command-line tool for Windows, macOS and Linux that converts and manipulates colors in a terminal rather than a GUI.
Similar software
Related functionality, not a direct replacement.
Pika
Pick colors from your screen with a macOS utility.
ColorSlurp
Color picker for Mac and iOS with a magnifier and palette management.
ColorZilla
Browser extension eyedropper, color picker and gradient generator.
WebAIM Contrast Checker
An online checker that tests foreground and background color contrast against WCAG AA and AAA levels.