HDR that looks washed out (flat, low-contrast) or too dark (crushed shadows) on a TCL Roku TV is almost always picture settings, not a defect. The two complaints have nearly opposite fixes, so figure out which you've got first: washed out = not enough contrast/saturation; too dark = shadows and overall brightness pulled down. Then adjust while HDR content is actually playing, because the HDR menu is separate from the SDR one.
Get to the right menu
HDR has its own picture settings on a Roku TV. Start playing HDR content first, then press the * (Star) button on the remote to open Picture settings — what you change there applies to HDR, not your regular SDR picture.
If HDR looks washed out (flat, grayish)
- Set the picture mode to Movie or Dark. Vivid and Normal can look flat and oversharpened on HDR. Movie (or "Dark") gives the most accurate, punchy HDR.
- Turn on Local Contrast / local dimming — set it High. This is what gives HDR its depth (bright highlights, deep blacks). On washed-out HDR it's usually off or Low.
- Check color temperature. A too-cool (blue) setting looks washed out; Warm is the accurate target for HDR.
- Don't crank Brightness to fix it. Raising the "Brightness" slider lifts black levels and makes it more washed out. Use Local Contrast and the right mode instead.
If HDR looks too dark (crushed shadows)
- It's partly normal — HDR puts brightness in the highlights. On a budget panel, the average image looks darker than SDR by design. But you can recover shadow detail.
- Raise the Brightness slider a little (this controls shadow/black level). Small steps — too much washes it out.
- Use the HDR picture mode, not the power menu. With HDR content playing, the mode list becomes HDR10 or Dolby Vision, each with a Dark, Normal and Bright variant — press the star button and pick Picture settings to reach them. Bright is what lifts a dim HDR image. Two traps: Settings > System > Power > Auto power savings only turns the TV off when idle and does nothing to picture brightness, and the Low Power picture mode does dim the image and is easily mistaken for it.
- Bump Local Contrast down a notch if shadows are being crushed to pure black — High local dimming can over-darken dark scenes on some TCLs.
A signal check
If HDR looks flat and the TV says it's only getting a limited signal, the port may not be in the enhanced mode: set the input's HDMI Mode to Enhanced/HDMI 2.0 (Settings > TV inputs) and check the cable: 4K/60 HDR needs a Premium High Speed cable (18 Gbps). Ultra High Speed (48 Gbps) is for 4K/120 and 8K, so it is more cable than this fault needs. A link that cannot carry the bandwidth usually makes the source fall back to a lower-bandwidth format, which is one way HDR arrives looking flat. This per-port setting drives most TCL picture faults — see the broader TCL HDMI and picture issues guide if color or flicker problems persist. If the port goes fully black instead of just washed out, that's the TCL HDMI no-signal / black-screen fix.
FAQ
Why does HDR look worse than SDR on my TCL? Usually the picture mode (use Movie/Dark) and Local Contrast off. Adjust the HDR settings while HDR content is playing — they're separate from your SDR settings.
HDR is too dark — is the TV faulty? Mostly it's by design (HDR loads brightness into highlights). Raise the Brightness slider a little and turn off any light-sensor/eco dimming.
Should I turn up the Brightness slider for washed-out HDR? No — that lifts black levels and makes it flatter. Use Local Contrast (High) and the Movie picture mode instead.
Why is my HDR flat and limited-looking? The HDMI port may be in Standard mode, or the cable can't carry HDR. Set HDMI Mode to Enhanced and use a Premium High Speed (18 Gbps) cable or better.