[Gllug] Perl Question - Spam Filter for NMS Form Mail

[Ryan Cartwright]

2009/2/9 Henry Gilbert <henry.gilbert at gmail.com>:
> 2009/2/9 Ryan Cartwright <r.cartwright at equitasit.co.uk>:
>> I'm colour blind and certain colour combinations have been known to
>> make me pass out, others can render text completely invisible. I don't
>> use a screen reader and have otherwise good vision. I would generally
>> view the same site as "the rest" but on some sites I just can't see
>> anything or the colours make me physically sick.
>>
>>
>
> Could you let me know please which combinations these are?

I have red/green colour-blindness (deuteranopia - the most common
form) but my experience tells me that even within the same form there
are variations and different people seem to struggle with different
levels of colour. BTW red/green does not mean I cannot see red and/or
green at all. The particular colour combinations that affect me are
bright red on bright green (#f00 on #0f0). A colleague once wore a
green shirt with red pinstripes and whilst most people found it
garish, I fell off table I was perched on! Bright yellow or green on
purple is similar. White on yellow (or vice versa) is pretty much
invisible as is green on blue. Similar shades of red green or blue
next to each other are difficult to distinguish as are mid-shaeds on
black. The best example I can give you is to imagine a barcode and you
eyes keep focussing between the white and black stripes alternately.
The result is a kind of vertigo which is what makes me pass out.
Traffic lights are not an issue because there is significant gap
between the lights and their order never changes.

But as I said, that's just me - different colours affect different
people. How do you know that what you see as bright red is the *same*
colour everybody else sees? All you know is that you can identify it
as such with the same regularity as they can - I can't. Playing
snooker is a nightmare - once the brown completely disappeared and I
had to get opponent to hold his finger over the ball.

> Also what kind of features would help you navigate such sites better?

The colours I've listed will probably seem a bad idea to put on a
website but quite a few sites will use mid blue on black and that's
hard to see. Contrast is the key but there's still no need to go to
entire hi-visibility (yellow on black).

http://www.vischeck.com/vischeck/
This site has some info on colour-blidnness including depictions ofn
what things look like to colour-blind people. Of course I can't tell
you how accurate they are because I can't see the original one
properly! For example on this page
http://www.vischeck.com/info/wade.php, the two strawberry photos are
almost identical to me (the right one is slightly greyer) so I guess
that's pretty accurate, but on other pages there's a greater
difference.

> I've been thinking a while about implementing stylesheet switchers and
> so on. But prefer not to implement things without prior experience or
> feedback.

Good browsers include stylesheet switching these days. I prefer not to
include things like text-size buttons on my sites. That will mean the
user only views your site in a different size etc. I think it's a
better policy to include information on setting your browser prefs so
that all sites are viewed at your preference. Sometimes within those I
will include links to switch the stylesheet there and then but the
emphasis should be on helping people use the tools within their
browser IYAM.

hope this helps
-- 
Ryan Cartwright
Equitas IT Solutions
http://www.equitasit.co.uk
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