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

[Olaf Schmidt]

Hi!

My experience with partially sighted people is that no two users are the same, 
so we need to make it really easy for the users to customise the colour 
schemes.

I also believe we should add a few well-looking colour schemes that are 
typical for the kind of choices many partially sighted users make.

I have met people who need:
a) a high contrast colour scheme with dark text on a light background (i.e. 
white-on-black, plus other very dark forground colours and very light 
background colours) for users that do not see things with too few contrast

b) a medium contrast colour scheme with pale light colours on a very dark 
background (e.g. grey-on-black, plus other pale light forground colours and 
very dark background colours) for users that are dazzled by even small bright 
areas and who do not see things with too few contrast

c) a high contrast colour scheme with very intense light colours on a very 
dark background (e.g. bright-yellow-on-black, plus other very bright 
forground colours and very dark background colours) for users that are 
dazzled by large bright areas and who do not see things with too few contrast

d) some users prefer the same as c) with simple white-on-black instead of 
light-yellow-on-black


I also like the idea of including a colour scheme for people with 
two-dimensional colour perception (i.e. red-green or yellow-blue colour 
blindness). These users perceive every colour as identical to some shade of 
red, blue, gray, black or white. That means that we could design

e) a colour scheme that uses the same tone of red (#FF0000), blue (#0000FF) 
and grey (#808080) with different brightness and saturation.


I am sure that all five colour schemes can be made well-looking even for 
normally sighted users. It is mainly important that the colour schemes are 
consistent in their colour choices (e.g. no inverted colours for selected 
text, and no intense colours in the pale-on-dark colour scheme).

The best strategy is probably to post screenshots of the new colour schemes to 
this list, so that we can try to get them evaluated by readers are (or who 
have access to) partially-sighted people.

Olaf