Visual contrast (#663)

* remove visual-contrast-of-text how-to

* Delete luminance-contrast-between-background-and-text.html

* remove font-characteristics-contrast method

* remove visual contrast of text guideline

* remove old draft methods

guidelines/index.html

@@ -233,28 +233,6 @@ <h4>Conveys hierarchy with semantic structure</h4>
 
 
 
-			</section>
-			<section class="guideline">
-				<h3>Visual contrast of text</h3>
-				<p class="guideline-text">Provide sufficient contrast between foreground text and its background.</p>
-				<section class="outcome" data-status="exploratory">
-					<h4>Luminance contrast between background and text</h4>
-					<p>Provides adequate luminance contrast between background and text colors to make the text easy to read.</p>
-
-				<div class="ednote">
-					<p>Visual Contrast is a migration from WCAG 2.1 with significant updates:</p>
-					<ul>
-						<li>New calculations of contrast based on more modern research on color perception.</li>
-						<li>Merging the 1.4.3 AA and 1.4.6 AAA levels into one guideline.</li>
-						<li>New test of text contrast.</li>
-						<li>At this time, it only includes textual visual contrast.</li>
-					</ul>
-				<p>We propose changing the names of <q>Contrast (Minimum)</q> and <q>Contrast (Enhanced)</q> to <q>Visual Contrast of Text</q> as a signal of a paradigm change from one about color to one about <q>perception of light intensity</q>. The reason for this change is that the understanding of contrast has matured and the available research and body of knowledge has made breakthroughs in advancing the understanding of <q>visual contrast</q>.</p>
-				<p>The proposed new guidance more accurately models current research in human visual perception of contrast and light intensity. The goal is to improve understanding of the functional needs of all users, and more effectively match the needs of those who face barriers accessing content. This new perception-based model is more context dependent than a strict light ratio measurement; results can, for example, vary with size of text and the darkness of the colors or background.</p>
-				<p>This model is more responsive to user needs and allows designers more choice in visual presentation. It does this by including multi-factor assessment tests which integrate contrast with inter-related elements of visual readability, such as font features. It includes tests to determine an upper limit of contrast, where elevated contrast may impact usability.</p>
-				<p>This outcome will eventually include a second rating approach based on the mean average APCA value for all text in a process and view based on a character count.</p>
-				</div>
-				</section>
 			</section>
 			<section class="guideline">
 				<h3>Error prevention</h3>