scRGB is a wide color gamut RGB color space created by Microsoft and HP that uses the same color primaries and white/black points as the sRGB color space but allows coordinates below zero and greater than one. The full range is −0.5 through just less than +7.5.
Negative numbers enables scRGB to encompass most of the CIE 1931 color space while maintaining simplicity and backward compatibility with sRGB by not changing the primary colors. However this means approximately 80% of the scRGB color space consists of imaginary colors. Numbers greater than 1.0 allow high dynamic range images to be represented, though the dynamic range is less than other formats.