colorsColorBlind Preferences


Tactile Interrogator has preferences to adjust the colors used for Age and Permission coloring. If you suffer from some kind of colorblindness, you can adjust the colors to fit your vision. Or, if you want, you can change the settings just to have fun with it, even if you're not colorblind. (There's a handy button to reset it to the defaults if you get lost.)


Colorblind Physics

Visible light is actually electromagnetic radiation with wavelengths in the range of about 400nm to 700nm. Our retinas contain sensors named 'cones' that respond to bands of wavelengths within that range. Light shorter than 400nm is 'ultraviolet' (beyond violet). Light longer than 700nm is 'infrared' (inside red). Both are invisible.

Usually, your red cones are most sensitive to a gaussian distribution of wavelengths around 600nm to 700nm. Green cones are most sensitive to 500nm to 600nm, and Blue cones to 400nm to 500nm. There's plenty of overlap, so that light at 600nm looks the same as a mixture of two kinds of light at 580nm and 620nm, at least to the human eye. (Spectroscopes can distinguish these and form an important part of scientific instrumentation that go way beyond what humans can see.)

Everybody's body chemistry is a little bit different, and everybody's cone sensitivity is a little bit different. The most common colorblindness comes when your green cones' sensitivity is shifted more torward the red, so that it's hard to tell greens, yellows and reds apart. A more severe kind comes when you have no green cones at all. These problems can also happen with blue or red cones. Some people have no cones at all, and rely on their rods for sight, which only provide black-and-white vision.

The details of your particular vision can be analyzed by an expert, but you don't need to go that far. What's important for your use of Interrogator is to find settings that are useful to you. All you need is to experiment yourself with the preference panels.


How to Adjust your ColorBlind Preferences

First, bring up the Preferences window by choosing the Preferences menu command:

X11: near the bottom of the Edit menu
Mac: on the Interrogator menu

The tab named Age chooses the colors for Age Coloring. The tab named Perm chooses the colors for Permission coloring. Exception: the Error color, in the Perm tab, is used both in Permission and Age Coloring.

For instance, if your colorblindness makes you confuse yellows and greens and browns, you might have trouble telling the difference between the age colors for 1 hour (yellow) and 1 day (green), so you might want to use the colors from green through blue to magenta for the whole age progression. Slide each color up the rainbow, closer to the blue-purple end of the spectrum. The colors on the preference panel, and in the directory windows themselves, change instantly as you make adjustments, so you can keep the windows open as you work. Adjust them until it seems right.


Handy Keystrokes

To show the color key:
X11: alt I
Mac: ^I
(The I letter stands for Info)

To toggle between Age and Permission coloring:
X11: alt G
Mac: ^G

To show the Preferences panel:
X11: altP altO
Mac: ^P ^O
(the Oh letter means Open)


Tips

Age colors are interpolated on a logarithmic scale between the colors you choose. Therefore, if you double-back, you will introduce ambiguities. Permission colors are always exactly at the color points, so you have more freedom to choose colors that make sense to you.

Note how the default Age colors tend toward greens, whereas default Permission colors are mostly purples. If you switch back and forth between Age and Permission coloring, you should keep the two in distinct parts of the rainbow, so it is always obvious which mode you are in.

Mixing a wide variety of colors from all over the rainbow would give you more precision in Age coloring, but the result might look ugly to your eyes.




Documentation > Color Blind Settings        

                     

T a c t i l e   I n t e r r o g a t o r   W e b s i t e