Table 1.10 Overview of the recommended luminance contrast in the EU countries Country Recommended luminance Remarks contrast DE Luminance contrast (K) is measured Optimal contrast: by the Michelson formula. White achromatic: K = - – ≥0.91 K 0.64: high contrast ≥ ≤0.99 K 0.83: subjectively chosen as achromatic: K = - ≥ – ≥0.97 contrast’ by visually (Negative) ‘optimal ≤0.99 impaired. Yellow achromatic: K = - – ≥0.89 Luminance contrast depends on the ≤0.99 surface of materials used (function Green achromatic: K = - – ≥0.88 of luminance, illuminance and ≤0.98 reflectance of the illuminated Blue achromatic: K = - – ≥0.84 surface) . (Negative) ≤0.95 Yellow lila: K = – ≥0.90 Yellow blue: K = – ≥0.87 White lila: K = – ≥0.92 blue: K = – ≥0.98 Green blue: K = – ≥0.91 Yellow red: K = – ≥0.83 - white sign on dark background: board should be 25% larger. NL Difference in reflectance between - For oriëntation, reflectance of: fore- and background: white = 0.85 0,30. black = 0.04 ≥ red (dark to light) = 0.10-0.35 yellow (dark to light) = 0.30-0.70 green (dark to light) = 0.05-0.60 blue (dark to light) = 0.05-0.50
Table 1.10 Overview of the recommended luminance contrast in the EU countries Country Recommended luminance contrast Remarks DE Luminance contrast (K) is measured by the Michelson formula. K ≥ 0.64: high contrast K ≥ 0.83: subjectively chosen as ‘optimal contrast’ by visually impaired. Luminance contrast depends on the surface of materials used (function of luminance, illuminance and reflectance of the illuminated surface) . Optimal contrast: White – achromatic: K = ≥0.91 - ≤0.99 – achromatic: K = ≥0.97 - ≤0.99 (Negative) Yellow – achromatic: K = ≥0.89 - ≤0.99 Green – achromatic: K = ≥0.88 - ≤0.98 Blue – achromatic: K = ≥0.84 - ≤0.95 (Negative) Yellow – lila: K = ≥0.90 Yellow – blue: K = ≥0.87 White – lila: K = ≥0.92 – blue: K = ≥0.98 Green – blue: K = ≥0.91 Yellow – red: K = ≥0.83 - white sign on dark background: board should be 25% larger. NL Difference in reflectance between fore- and background: ≥ 0,30. - For oriëntation, reflectance of: white = 0.85 black = 0.04 red (dark to light) = 0.10-0.35 yellow (dark to light) = 0.30-0.70 green (dark to light) = 0.05-0.60 blue (dark to light) = 0.05-0.50