Warm, neutral, or cool
Move toward warm to reduce blue light. Return to neutral whenever you want to remove the tint.
Display Dimmer Pro
Blue light filter for Windows
Choose warmer screen colors with Display Dimmer Pro. Use the Temperature slider to reduce blue light, fine-tune each display, and put your preferred settings on a schedule.
Choose each display
Set monitors individually or choose All Displays to apply the same temperature across your enabled displays.
Make it automatic
Use Pro schedules, app rules, and hotkeys to bring your preferred screen colors into your daily routine.
How to turn on the blue light filter
In Display Dimmer, look for Temperature. This is the control for warmer or cooler screen colors.
- Show the slider. Open Settings → General → Appearance. Under Sliders, enable Show temperature slider. If Temperature is already visible in the main window, skip this step.
- Choose a display. Return to the main window and select a monitor from the display dropdown. Choose All Displays if you want the same setting on all enabled displays.
- Unlock or preview. If you already have Pro, the slider is ready. Otherwise, click the Temperature slider and choose Preview free to start the 30-minute preview, or unlock Pro.
- Move left toward warm. Drag toward the orange side until the screen has the warmer tone you prefer. Main-window adjustments take effect as you move the slider.
The preview gives you time to try the filter on your own setup. It does not unlock the other Pro features or remove the free version’s automation limits.
What the Temperature slider changes
A blue light filter changes the screen’s color balance. Display Dimmer’s warm settings reduce the blue channel relative to red, giving whites and other colors a warmer appearance. Brightness and Temperature remain separate controls.
Left: warmer colors
Move toward orange for a warmer image and less blue. Start gently, then increase warmth if you prefer a stronger effect.
Right: neutral, then cooler
Move back toward Neutral to remove the tint. Continuing farther right selects cooler colors, which are not the blue-light-reducing setting.
Watch the readout: Warm, Neutral, or Cool, followed by an approximate Kelvin value. Lower Kelvin labels mean warmer colors. The neutral point reads Neutral · 6,500 K and sits near the right side, not in the middle.
The numbers help you compare settings; they are not calibrated measurements of your monitor or a measured percentage of blue light removed. Two displays can look different at the same setting, so adjust them individually when needed.
If All Displays shows Mixed, your displays have different temperatures. Moving the slider applies one chosen temperature to all enabled displays in that selection.
Turn the filter off without changing brightness
Select the display you want to change, then move Temperature back to Neutral · 6,500 K. This removes Display Dimmer’s temperature tint while leaving your brightness and contrast settings alone.
- Hiding is not disabling. Turning off Show temperature slider hides the control, but keeps the current temperature applied.
- Reset levels changes more. The main window’s Reset levels button also resets brightness and contrast. Use the Temperature slider if you only want to remove the tint.
- Check active rules. If a schedule or app rule controls temperature, edit that rule as well when you want to change its automatic behavior.
Schedule warmer colors or use a shortcut
With Pro, temperature fits into the same schedules, app rules, and hotkeys you use for brightness.
Warmer colors in the evening
Open Settings → Schedules. Add or edit a schedule, choose its times, enable the power toggle beside Temperature, and select a warm setting. Check the brightness setting too, then click Apply.
Different colors for specific apps
Open Settings → App Rules. Add or edit a rule for an app, enable its Temperature toggle, and choose warmth or Neutral. Check the rule’s brightness setting, then click Apply.
Turning a rule’s Temperature toggle off excludes temperature from that rule; it does not mean “set the display to Neutral.” To request neutral colors explicitly, leave the toggle on and choose Neutral.
For keyboard control, open Settings → Hotkeys and choose Temperature down for warmer colors, Temperature up for cooler colors, or Set temperature for a specific setting. Save with Apply. See the hotkeys guide for shortcut setup and display targeting.
Hotkey temperature values use the slider’s 0–100 position, not Kelvin: 89 is Neutral. Do not enter 6,500 as a hotkey value.
Brightness, color accuracy, and compatibility
Display Dimmer applies temperature through software color adjustments, even when DDC/CI handles your monitor’s hardware brightness. You do not need to disable DDC/CI to use warmer colors. Learn more about hardware brightness and software gamma control.
- Keep color-critical work neutral. Warm settings intentionally change color balance. Return Temperature to Neutral for photo editing, design, or other work where you need to judge colors.
- Check that the display is enabled. If the slider is unavailable despite Pro or an active preview, make sure control is enabled for the selected display.
- Results depend on the display path. Graphics drivers, HDR modes, and connected displays can affect software color control. Preview the filter on your own setup before buying; not every configuration accepts the same adjustments.
- Avoid competing adjustments while testing. Windows, your GPU, or another color-control app can change or reset software colors. Temporarily turn off other color filters when checking Display Dimmer’s effect.
If your screen is too bright as well as too cool, adjust brightness separately. The screen dimmer guide explains dimming, and the troubleshooting hub covers common display-control problems.
Frequently asked questions
Is the blue light filter free?
Blue light filtering and color temperature are Pro features. Free users can start a 30-minute preview once per day. The timer runs continuously after it starts; closing the app does not pause it. Pro is a one-time purchase with no subscription.
What happens when the free preview ends?
Temperature returns to Neutral. Temperature settings in schedules and app rules are cleared, while their brightness settings and the rules themselves remain. Upgrade to Pro for ongoing temperature control.
Why is the neutral point not in the middle?
The slider gives more room to warmer settings. Look for the Neutral · 6,500 K readout near the right side, rather than treating the middle as neutral. Kelvin values are approximate, not calibrated measurements.
Does hiding the Temperature slider turn the filter off?
No. Hiding the slider only removes the control from the main window; the current temperature stays applied. Return Temperature to Neutral to remove Display Dimmer's color tint.
Find the warmth that suits your setup.
Install Display Dimmer free and try the blue light filter for 30 minutes. Keep temperature control with Pro: one-time purchase, no subscription.