TIP #403: WEB COLORS FOR TK 
=============================
 Version:        $Revision: 1.3 $
 Author:         Jan Nijtmans <jan.nijtmans_at_users.sf.net>
 State:          Final
 Type:           Project
 Tcl-Version:    8.6
 Vote:           Done
 Created:        Sunday, 17 July 2011
 URL:            https://tip.tcl-lang.org403.html
 Discussions-To: Tcl Core list
 Post-History:   

-------------------------------------------------------------------------

 ABSTRACT 
==========

 This TIP proposes some modifications in the RGB values of various 
 colors as used in Tk, bringing those colors more in line with various 
 W3C standards. 

 RATIONALE 
===========

 There is a difference between the color definitions in X11 and the 
 color definitions in Web standards like html and css. For example HTML4 
 defines the basic color names *aqua*, *fuchsia*, *lime*, *olive*, 
 *silver* and *teal*, which are currently not known to Tk. Making things 
 worse, some colors like *green* and *gray* have a different RGB value 
 in X11 compared to the html4 specification. See: 
 <URL:http://www.w3.org/TR/css3-color/#html4> 

 SPECIFICATION 
===============

 This document proposes: 

     * Add the colors *aqua*, *crimson*, *fuchsia*, *indigo*, *lime*, 
       *olive*, *silver* and *teal* to the list of recognised colors, 
       both for win32 and X11. For X11 it will be built in the wrapper 
       function /TkParseColor/, which is a thin wrapper around 
       /XParseColor/. The RGB values used are those from the above 
       mentioned html4 specification (6 from the basic colors, 2 from 
       the extended colors). 

     * Modify the RGB values of *gray/grey*, *green*, *maroon* and 
       *purple* matching the html4 specification. Those 4 colors are the 
       only ones that differ in X11. Applications using those colors 
       will change in visible appearance. 

       *POTENTIAL INCOMPATIBILITY* 

 COMPATIBILITY 
===============

 On the script level nothing changes, only applications one or more 
 colors from the list *gray*, *grey*, *green*, *maroon* and *purple* 
 will change in visible appearance. A side-by-side visible difference 
 between those 4 colors can be seen at: 
 <URL:http://en.wikipedia.org/wiki/X11_color_names#Color_name_clashes> 

 ALTERNATIVES 
==============

 None 

 REFERENCE IMPLEMENTATION 
==========================

 A reference implementation is available at <URL:http://core.tcl.tk/tk> 
 in branch /jn-web-colors/. It contains a test-case /color-1.5/, which 
 checkes the RGB values of all known X11 colors with the above 
 modifications. This test is marked /nonPortable/, simply because I 
 don't know how many older X11 color lists are still in use. On win32, 
 mac and any reasonable recent X11 package, this test passes. 

 COPYRIGHT 
===========

 This document has been placed in the public domain. 

-------------------------------------------------------------------------

 TIP AutoGenerator - written by Donal K. Fellows