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Re: [css] Proposal: making Shorthand Hex Colors even shorter (16 grayscale shades)

From: Alan Gresley <alan@css-class.com>
Date: Tue, 06 Sep 2011 12:01:32 +1000
Message-ID: <4E657EFC.7020108@css-class.com>
To: Marat Tanalin <mtanalin@yandex.ru>
CC: "Tab Atkins Jr." <jackalmage@gmail.com>, www-style@w3.org
On 6/09/2011 9:32 AM, Marat Tanalin wrote:
> 06.09.2011, 03:03, "Tab Atkins Jr."<jackalmage@gmail.com>:

>> I don't understand how you think rgba() is wrong and how it can be
>> replaced by 'background-opacity'.  Colors are used in far more than
>> just 'background-color'.  Partially-transparent border or text
>> colors are useful, and specifying them with an alpha color is
>> simple (better than adding 'border-color-opacity' and
>> 'color-opacity' properties, for certain).  Alpha colors are also
>> very useful as color-stops in gradients, where there is absolutely
>> no way to replace them with a property.
>
> Just most often rgba is used for background in practice. You are
> right that it might be used with border-color or color (though,
> e.g., semi-transparent text color is used far rarely).

Don't forget that rgba can also be used for text-shadow and box-shadow 
[1]. Also, rgba can be build up in layers to produce more colors [2] [3] 
(example is with hsla).

>> After more thought on the matter of 1- or 2-digit hex shorthands,
>> though, I've now come down against it.  I gave my reasoning against
>> 2-digit grays previously in the thread (the expansion rule is
>> different than for 3-digit color).
>
> Even if expansion rule is different, it does not mean this is
> something bad.
>
>> As for 1-digit grays, I no longer think they're a good idea.  When
>>  Colors 4 gets written I'll be pushing for (or writing, if I end
>> up the editor) 4- and 8-digit hex colors so you can specify alpha
>> without having to switch to rgba() and convert your components to
>> decimal.  I don't think it's good to add a new hex variant that
>> can't similarly receive an alpha.  (Obviously, having #0 expand
>> into #00000000 isn't useful.  Adding a second digit, like having
>> #0c expand into #000000cc, is just confusing.)
>
> rgba values (including its probable hex syntax) is a topic for
> another thread (if someone needs it at all) and is quite alien thing
> in this thread, in my opinion. Let's try to isolate regular
> hex-values discussion here.

I don't see why you say this. rgba and 8-digit hex color are the same 
thing. rgb and 6-digit hex color are the same thing. The only difference 
between the two are their notation. I am in agreement with Tab here. #0c 
expanding into #000000cc is not a good thing and can lead to confusion.

>> The benefit of 1-digit grays is extremely minimal.  You get to hit
>> a key once instead of three times.  It's the same key all three
>> times, too, so the burden of hitting it thrice is basically nil.
>
> It's not about key-hitting. #ccc just _redundant_ compared with #c.

#ccc became redundant in a sense when 32-bit processors came out. I 
would suggest you read about the development of computer color and true 
color [4].

> So, if we able to shorten #cccccc to #ccc, then shortening #ccc to
> #c (as well as #acacac to #ac) seem just logical.

It's not about shortening. The reserved has happened. Please read about 
web-safe colors [5].

>> I am still okay with a gray() function, though, which takes a
>> single number/percentage, and then optionally an alpha value.  I'm
>> not sure if we *need* it, but I'm favorably disposed to it.
>
> The topic is not about some new functions, it's about shortening
> existing hex values.

I would recommend that you look into the concept or reasoning behind a 
gray() function. I see no reason to shorten hex values where their use 
was for a legacy 16-bit processor. You seem to be making a argument that 
#ccc was created as a shorthand for #cccccc where the reverse is true.


1. http://css-class.com/test/css/shadows/text-shadow2.htm
2. http://css-class.com/test/css/colors/color-transparent1.htm
3. http://css-class.com/test/images/hsla-color-merging.png
4. http://en.wikipedia.org/wiki/Color_depth#Truecolor
5. http://en.wikipedia.org/wiki/Web_colors#Web-safe_colors


-- 
Alan Gresley
http://css-3d.org/
http://css-class.com/
Received on Tuesday, 6 September 2011 02:01:27 GMT

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