Test Case sc1.4.1_l2_005: Enough contrast for foreground diagram and background colour

Formal Metadata

Formal Metadata
TitleEnough contrast for foreground diagram and background colour
DescriptionDocument containing a diagram on a background colour.
CreatorBenToWeb (johannes.koch@…)
RightsCopyright BenToWeb 2005-2007
LanguageEnglish
Date2005-08-11
Statusaccepted QA

Technologies and Features

Technologies are markup languages or data formats. If the technology is a markup language, “features” refers to elements and attributes.

XHTML™ 1.0 The Extensible HyperText Markup Language (Second Edition)

XHTML™ 1.0 The Extensible HyperText Markup Language (Second Edition)

CSS 2.0 Specification

CSS 2.0 Specification

Test Data

Purpose

The test is intended to fail because the luminosity contrast ratio between diagram colour/page background colour is higher than 5, but between diagram colour/diagram background colour is lower than 5.

Expert Guidance

The formula to be used for calculating the luminosity contrast ratio can be found at http://www.w3.org/TR/2006/WD-WCAG20-20060427/appendixA.html#luminosity-contrastdef.

Test Modes

Accessibility expert.

Test Files

Test file.

TCDL Data

sc1.4.1_l2_005 (XML).

Rules

“Rules” refer to success criteria in WCAG 2.0, checkpoints in WCAG 1.0 and similar requirements.

Primary Rules

The test case fails the following success criterion: http://www.w3.org/TR/2006/WD-WCAG20-20060427/guidelines.html#visual-audio-contrast-contrast.

Functional Outcome

The foreground and background colours have not enough contrast.

Technical Comment

The luminosity contrast ratio between diagram and page background is 15.60, between diagram colour and diagram background is 4.00.

Secondary Rules

Secondary Rule (WCAG 2.0 - June 2005 Working Draft)

The test case needs review before it can be established if it passes or fails the following success criterion: http://www.w3.org/TR/2006/WD-WCAG20-20050630/#visual-audio-contrast-contrast.

Functional Outcome

The WCAG WG hasn't provided threshold values for colour contrast yet.