What Is BT.2020 Color Space? The UHD HDR Color Standard Explained

BT.2020 (also called Rec. 2020) is the color space standard defined by the International Telecommunication Union (ITU) for Ultra High Definition (UHD) television. It covers approximately 76% of the CIE 1931 color space — significantly wider than DCI-P3 (45%) and dramatically wider than sRGB (35%). BT.2020 is the target color space for HDR content mastered in 4K UHD.

However, BT.2020 is a theoretical target more than a practical reality. No current consumer display can reproduce the full BT.2020 color space — the best OLED and Mini LED displays cover 70–80% of BT.2020, and most cover only 50–60%. HDR content is mastered in BT.2020 but displays render it in DCI-P3 (the practical wide gamut). The display maps the BT.2020 colors to its actual gamut, which may be smaller.

This guide explains what BT.2020 is, how it relates to sRGB and DCI-P3, why no display covers it fully, and what it means for HDR content. By the end, you'll understand this often-mentioned but poorly understood color space and its role in the HDR pipeline.

BT.2020 defines color primaries that are more saturated than any current display technology can reproduce. The BT.2020 green primary (0.170, 0.797) is a pure spectral green at 532nm — extremely saturated. Current OLED and LCD displays use red, green, and blue emitters that aren't pure spectral colors; they're broader-spectrum light sources that can't reach the extreme saturation BT.2020 requires.

The closest technology to BT.2020 is laser projection — pure spectral lasers can reach BT.2020 primaries. Some professional cinema projectors (Christie, Barco) use laser illumination and cover 90%+ of BT.2020. But consumer displays (OLED, LCD) use LEDs or OLED emitters that produce broader-spectrum light, limiting them to 50–80% BT.2020 coverage.

The practical implication: HDR content is mastered in BT.2020 (the standard requires it), but displays render it in their actual gamut (typically DCI-P3). The display maps the BT.2020 colors to its gamut, which may compress or clip the most saturated colors. This is why two HDR displays with different gamut coverage can look different — the one with wider gamut (closer to BT.2020) shows more saturated HDR colors. For more, see our color gamut test and the DCI-P3 vs sRGB guide.

When a display receives BT.2020 content but can't reproduce the full BT.2020 gamut, it must map the BT.2020 colors to its actual gamut. This is called color mapping or gamut compression. There are two approaches: hard clipping and soft compression.

Hard clipping maps BT.2020 colors outside the display's gamut to the nearest in-gamut color. This preserves saturation for in-gamut colors but causes saturation loss for out-of-gamut colors — vivid BT.2020 reds may become less saturated DCI-P3 reds. Most consumer displays use hard clipping because it's simple and preserves perceived saturation.

Soft compression (also called tone mapping) gradually compresses out-of-gamut colors into the display's gamut, preserving relative relationships between colors. This produces more natural-looking color but reduces overall saturation. Professional reference displays use soft compression for the most accurate color rendering. For more on color spaces, see the ITU BT.2020 specification and the Wikipedia article on Rec. 2020.