DisplayPort to HDMI Adapter for TV: Fix Limited RGB

October 31, 2026

By ZONG Editorial Team | ZONG technical guide

Quick answer: Set the source to full range RGB, then rename the television input to PC. That single change removes the grey blacks that send most buyers back to the shop. Confirm the adapter passes 4K60 at 18 Gbps, supports HDCP 2.2 on both sides and carries HDR metadata if the source offers it. Check the input label before blaming the cable, because a range mismatch looks exactly like a faulty adapter. Change one setting at a time so you know which one fixed it.

A television is the most common HDMI sink in the world and the least predictable. It advertises 4K60, HDR and HDCP 2.2 in its EDID, then shows a washed-out desktop because it has interpreted the signal as limited range RGB. The adapter is rarely at fault. What decides the result is the handshake between the DisplayPort source, the adapter and the television input settings.

Why a TV is not a monitor

A monitor expects full range RGB, 0 to 255, and displays it without interpretation. A television expects video range, 16 to 235, because broadcast material is coded that way. Send full range to a set that expects video range and blacks lift and whites clip. Apply video range to a full range signal and the image goes flat.

The input label is the lever. Most sets run a different processing chain on an input marked PC, which skips the range conversion and much of the edge enhancement. Left at the default label, the same signal looks soft.

What the EDID claims

A modern television EDID lists 4K60, HDR10 and HDCP 2.2. It also lists the colourimetry and the supported range. Reading it takes a minute and prevents most arguments about which part is at fault.

What the adapter must pass

The adapter must pass the timing, the metadata and the encryption without altering them. One that strips HDR metadata still shows a picture, but the television stays in SDR and the customer reports dull colour rather than a fault.

HDR metadata and HDCP 2.2

Two things travel alongside the picture and both are easy to lose in a cheap adapter. HDR metadata tells the television how to map the frame, and HDCP 2.2 encrypts it. Neither affects resolution, which is why failures here get misread as display quality problems.

When HDR disappears quietly

If the adapter drops the static metadata, the set stays in SDR and the picture looks flat but otherwise correct. Check the television info banner. If it reports SDR while the source reports HDR, the metadata is not reaching the sink.

Why HDCP 2.2 fails loudly

HDCP failure is not subtle. Protected content shows a black screen or an error because the source refuses to send unprotected video. The adapter must terminate HDCP 2.2 on the DP input and re-establish it on the HDMI output.

Adapter options and the label

The part matters less than most buyers expect. The setting behind it matters more.

The label that fixes the picture

Rename the HDMI input to PC, then set the source to full range RGB and the television to the matching range. On sets without a PC label, look for an HDMI black level or range setting and set it to full or high.

Refresh rate and judder

A television often accepts 4K60 but drives its panel at a multiple of 24 or 50. Use 60 Hz for desktop work and 23.976 or 24 Hz for film, and enable the set motion handling last rather than first.

Adapter type	4K60	HDR pass	TV fit
Passive adapter	Yes, short lead	Metadata only	Modern set, 1 m lead
Active adapter	Yes	Yes	Any 4K60 set
Adapter with audio out	Yes	Yes	Soundbar or amplifier
Powered converter	Yes, scaled	Limited	Older 4K30 set
Dock or hub	Shared	Yes	Laptop, one cable

Real installations

Two living room jobs, both solved at the input label rather than at the adapter.

Home office, 55 inch set

A desktop ran 4K60 to a 55 inch television through a passive adapter. The desktop looked grey and text edges were soft. Renaming the input to PC and setting full range restored black, and the measured black level fell from 0.11 to 0.04 nits.

Gallery install, four screens

Four 4K60 sets ran from one DP 1.4 source through an MST hub with two streams. Two sets were left in video range and looked washed out beside the others. Matching all four to full range and one picture mode removed the mismatch without changing any hardware.

Frequently asked questions

Why does my TV show washed-out colours from a PC?

Almost always a range mismatch. The source sends full range RGB and the television expands it again, or the reverse. Set the source to full range and rename or reconfigure the input to match.

Does a DisplayPort to HDMI adapter support HDR?

Only if it passes the metadata through. Many passive adapters carry the timing but not the metadata, so the set stays in SDR. Check the television info banner rather than the packaging.

Do I need HDCP 2.2 for streaming apps?

Yes. Protected streaming needs HDCP 2.2 end to end. An adapter limited to HDCP 1.4 shows a black screen on protected titles while unprotected desktop content still displays normally.

Why is 4K60 greyed out on the TV?

Either the adapter or the lead cannot sustain 18 Gbps, or the input is set to a limited mode. Try a shorter lead and enable the enhanced or high bandwidth format for that input.

Should I use 60 Hz or 50 Hz?

Match the content. Desktop work and games suit 60 Hz, film suits 23.976 or 24 Hz, and broadcast in Australia suits 50 Hz. Letting the source switch per application avoids most visible judder.

Next step

Tell us the television model, the source and whether HDR or protected streaming is involved, and we will confirm the adapter and settings combination that gives 4K60 with correct range and metadata. Ask the team at https://zh-zong.com/contact/, email zongcarrie@zh-zong.com or call +86 13543026126.