private static float gammaCorrection( float value ) {
		return (value <= 0.03928f)
			? value / 12.92f
			: (float) Math.pow( (value + 0.055) / 1.055, 2.4 );
	}
Calculates the luma (perceptual brightness) of the given color.
<p>
Uses SMPTE C / Rec. 709 coefficients, as recommended in
<a href="https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef">WCAG 2.0</a>.

@param color a color
@return the luma (in range 0-1)

@see <a href="https://en.wikipedia.org/wiki/Luma_(video)">https://en.wikipedia.org/wiki/Luma_(video)</a>
@since 2
flatlaf-core/src/main/java/com/formdev/flatlaf/util/ColorFunctions.java