The Color Tutor application
There are many freeware color pickers, color mixers, color analysers and similar applications available on the Web. This one is specifically designed to complement our Color Tutorial with hands-on demonstration of the principles explained there. We've provided a set of exercises (links also at left and below), and it should also be useful as a tool for Web developers to ensure that their color schemes provide sufficient contrast between text and background. The application was coded in JavaFX™ by Antoine Poulet; concept and design by Tom Jewett.
Known limitations and bugs (v.1.0)
- Program download and operation were initially tested in Windows XP and Vista with IE7 & 8, Firefox, Safari, and Chrome, and on the Mac (2009) with Firefox and Safari. We recently (2013) had trouble with Mac OS X 10.6 but were successful after downloading the latest JavaFX runtime. If you encounter problems with any platform or browser, please let us know.
- When the application starts, it might not receive focus from the operating system; simply activate it as you would any other window on the screen.
- The eyedropper cursor cannot be operated with arrow keys.
- Yes, we desperately need new icons!
See also "Wish list" at bottom of page. As with all new programs, we need your help and feedback! Please email tom [at] tomjewett [dot] com—we'll be happy to keep you informed of updates, if you'd like.
Java runtime environment
To run this application, you will need only the Java Runtime Environment (JRE, possibly now called JavaFX Runtime). This is platform dependent—if it is missing, you should be given instructions when you click the download link below.
License: Freeware. Copyright 2009, Antoine Poulet and Tom Jewett. You may run or download this application for non-commercial use and use it on as many computers as you own (including school labs). You are welcome to link to this page (e.g., from syllabi, resource lists, blogs, rating sites, etc.). However, you may not re-post or re-distribute the application in any form, whether modified or not, without specific permission from the authors.
Run or download: In your browser, open the Java start file (.jnlp) for this application. The response will be browser-dependent:
- You may be given a choice to run the start file (.jnlp) or save it to your computer. Running it directly from the link will always give you the latest version with no further action on your part; saving it lets you simply click to run it locally. (You may have to re-download if there are changes to the start file.) Some browsers may show the file downloading to a temporary internet folder, without giving you a choice.
- The actual application (.jar file) will then be retrieved from the Web, and it may take some time to start up. You may be warned that the digital signature cannot be verified from publisher "Antoine". You can get rid of this by checking the "Always trust" box and then the Run button.
- Possible bug: When the program starts, it may not receive foreground focus from the operating system; you may have to hunt for it underneath other programs running on your screen.
RGB panels (foreground and background)
- R, G, and B sliders: control red, green, and blue values from 0–255. May be operated with mouse or arrow keys when the control has focus.
- R, G, and B text boxes: display value of sliders and permit entry of specific values. To enter a value, click or tab to the box, type a decimal value from 0–255, and finish by tabbing to the next control or clicking elsewhere.
- Hex value: displays the RGB value in the form normally used in style sheets for color and background-color attributes. Also permits entry of specific values as in the R, G, and B text boxes. You do not need to type the "#" sign.
- Eyedropper: allows picking a color from anywhere on the screen. Clicking this control produces a cross-hair cursor; clicking on the cursor position enters the selected pixel's value in the appropriate foreground or background RGB/HSB controls. Right-clicking on the cursor will exit without selecting a color.
HSB panels (foreground and background)
Color panel (center of application)
- Replace crosshair cursor for eyedropper control with a more intuitive one, or better with a magnifying one.
- Although we removed the menu from the beta version, we'd like to restore a "reset colors" function, perhaps with a button.
- Use a higher-resolution version of the program icon!
Copyright 2009‐2013, Tom Jewett,
tom [at] tomjewett [dot] com
Department of Computer Engineering and Computer Science, Emeritus
California State University, Long Beach