[Kde-accessibility] how blue must blue be for blue-on-yellow color scheme?

[Brian Cameron]

Gunnar:

I guess I don't really understand the need to figure out exactly what
colors make the most sense.  Why not just provide a single white on black
theme, and then allow users to modify/configure the two colors to whatever
they want.  This would allow people (regardless of disability) to pick the
colors that make the most sense for them.  Perhaps the configuration tool
could suggest a few color combinations that people think make sense for
various disabilities.  But as long as it is configurable, users will be
able to get what they need.

I'd think it would be fairly easy to take a 2-color white/black icon
and recolor it with two other colors on the fly.  This seems more sensible
than spending a lot of time creating multiple icon themes that are identical
except for the color usage.

Brian


> On Montag, 21. Januar 2008, Matthew Woehlke wrote:
>> [...]
>> Ok, so I keep hearing that blue-on-yellow colors are for a11y
>> specifically... that being the case, I suppose I'm going to go ahead and
>> add that scheme to kdea11y.
> 
> I created all three high-contrast themes (black on white, white on black, 
> and yellow on blue) for KDE 3.x after I read somewhere that they are 
> necessary. However, I did not really ask for specific reasons at that 
> time, and the only color scheme where I had input from people with low 
> vision is the white-on-black color scheme, so I do not know whether the 
> yellow-on-blue color scheme really meets the needs of those persons that 
> may need such a color scheme.
> 
>> What doesn't entirely make sense to me is what's wrong with
>> white-on-black for most cases (rod deficiencies as opposed to cone
>> deficiencies, where someone can tell about colors but not lightnesses?).
>> Anyway... how important is it that the blue be #0000ff as opposed to
>> #0000c0 and there-abouts?
> 
> I would guess that people with rod deficiencies are unusual. From my basic 
> knowlodge about how the eye works I would guess that even these people can 
> tell the difference between white and black, but they might not be able to 
> differentiate different shades of gray that easily.
> 
> I know, however, that there are people that need a high contrast, mostly 
> dark color scheme, but for whom white text on a black background is a too 
> large contrast (they are dazzled by the white and therefore cannot read 
> what is written). I would expect that the yellow-on-blue color scheme is 
> needed for these persons as yellow is darker than white (and brighter than 
> blue) and blue is brighter than black (and darker than yellow).
> 
>> Put another way, would the scheme in [1] (that tries to balance being
>> blue-on-yellow with "something that won't cause blindness in 'normal'
>> people ;-)") be adequate, or do things really, really need to be
>> #ffff00-on-#0000ff?
>>
>> 1: http://img178.imageshack.us/img178/3632/olympusrh8.png
> 
> As I have said above, I created the yellow-on-blue color scheme without 
> feedback from users of it. In fact, it is a modification of an earlier 
> version of the white-on-black color scheme where white is replaced by 
> yellow and blue is replaced by black.
> 
> If my assumption about possible users of the color scheme is correct, I 
> would argue that the scheme you suggest is problematic in the way that it 
> increases the contrast of the yellow-on-blue color scheme by partly 
> lightening the yellow and partly darkening the blue.
> 
> That said, the theme looks much better than my attempt on a yellow-on-blue 
> color scheme to my non-impairmed eyes (but as I said, it may not be what 
> the users of a yellow-on-blue color scheme need).
> 
> 
>> Matt Blissett [...] noted that the selection could use more contrast
>> (actually,  there is already more contrast than in the KDE3 version,
>> but it's still not very good). What's the safest way to do that; make
>> the selection  lighter, or everything else darker? Or is it "good enough"
>> and changing it is likely to cause problems?
> 
> Please keep in mind that persons with low vision need a good contrast 
> between the text and the background color in order to be able to read. 
> Differentiating the brightness between two different shades of background 
> colors can be done with a far smaller difference than reading text.
> 
> I hope that my comments are usefull for you,
> 
> Gunnar Schmi Dt
> 
> 
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