The Kontrast HandbookCopyright © 2022 Carl Schwan
Kontrast is a color contrast checker that allows users to verify if their color combinations are accessible for people with color vision deficiencies.
Table of Contents
IntroductionKontrast allows the user to check the contrast ratio between colors and determine if the result is suitable for people with color vision deficiencies. Users may select colors in a variety of ways, for example, by inputting the hex values manually, or by using the color picker tool to select any color value on their screen.
The contrast ratio check by this application is related to the difference in color between two objects that allows them to be distinguished. A contrast value of 21 indicates a perfect contrast (usually black on white) and a value of 0 indicates that the two colors are the same. The colors are checked against Web Content Accessibility Guidelines (“WCAG”).
Using Kontrast
After opening the application, you will be presented with a screen similar to the one above - this is the main screen of Kontrast and contains most of its features. A randomly selected text color, background color and their contrast ratio will be displayed as an example.
There are five main ways in which colors can be selected for comparison. These are outlined below.
If you know the hex values of the colors that you would like to check, then you can input them directly. To do so, click on the hex value of the sample color currently on the screen and type in the desired value.
If there is a color that you currently have on the screen - for example, from a sample image - then you can use the color picker tool to input this color directly into the application. To do so, click the color picker icon to the right of the hex value of the currently selected color, and click the color anywhere on the screen that you would like to sample. The color will then be selected in the application.
If you would like to tweak your current selection to see if certain changes have an effect on the contrast, then you can do so by using the hue, saturation and lightness sliders. These are located underneath the hex value of the current selection. The color selection will automatically update as you make changes to these sliders.
The button will swap the two currently selected colors, setting the background color as the text color and vice versa.
Menu OptionsThis chapter describes all application features accessible after clicking the icon in the top left corner.
This is the default screen of the application, allowing the user to select colors and view their contrast ratio. The functionality is described in the previous chapter.
Credits and LicenseKontrast
Program copyright 2020-2022 Carl Schwan (carl AT carlschwan.eu)
Documentation Copyright (c) 2022 Vlad Rakhmanin (vladimir.rakhmanin AT ucdconnect.ie)
This program is licensed under the terms of the GNU General Public License.