Summary and Minutes of Silver meeting of 20 December 2019

== Summary ==

A spirited discussion of the new formulas for visual contrast and a 
table for interpreting them.  It took the entire meeting. Highlights:

  * The math and pseudocode for are in the visual contrast
    <https://docs.google.com/document/d/1lmTpfgublIqRggMVbrwo55FMlyJo3Avp_TAvpuFttxI/edit#>
    draft.  Only look at pages 1-7.  Pages 8 and up are older versions
    being saved for the moment.  The new formula is based on solid
    science of perception.  It is not adapted for different monitors and
    ambient conditions, although it can be expanded to do that in the
    future if desired.
  * The font sizes are based on the CSS reference pixel.  There was
    discussion of the need for the point equivalent for designers and
    tools that still use points.  We agreed to provide both.  While
    there was discussion of print, we aren't doing contrast for print in
    SIlver.
  * We discussed the table of Acceptable Results.  While the table
    provides equivalencies to current WCAG for comfort, it turned out
    that those equivalencies generated a lot of discussion because it
    appears that we are making the requirements much tougher.  This is
    deceptive because WCAG 4.5:1 values are not uniform across the
    visual spectrum.  For example, darker colors may meet WCAG 4.5:1,
    but actually are perceived as being much lower, such as 3:1.  The
    lighter colors are more equivalent to WCAG 4.5:1.
  * We discussed the 3 color problem which is part of the reason that
    WCAG used a lower 4.5:1.  This is covered in the table as a separate
    category.  The apparent change to 7:1 is only for blocks of text
    that are using a thin stroke font.  Blocks of colors are not
    changing substantially, as are bold or large fonts.  It's the width
    of the color that is important for contrast.
  * We agree that the document we want to use a narrow scope for the
    first draft and that the section of pseudocode is in good shape for
    the first draft.  More help is needed to write Methods.

There will be informal meetings happening over the holidays during the 
regular meeting times (not the Conformance meeting time), but there will 
be no formal meeting until 7 January.


== Minutes ==

https://www.w3.org/2019/12/20-silver-minutes.html