Mix color channels



Using the Channel Mixer adjustment, you can create high-quality grayscale, sepia tone, or other tinted images. You can also make creative color adjustments to an image. To create high-quality grayscale images, choose the percentage for each color channel in the Channel Mixer adjustment. To convert a color image to grayscale and add tinting to the image, use the Black & White command (see Convert a color image to black and white).

The Channel Mixer adjustment options modify a targeted (output) color channel using a mix of the existing (source) color channels in the image. Color channels are grayscale images representing the tonal values of the color components in an image (RGB or CMYK). When you use the Channel Mixer, you are adding or subtracting grayscale data from a source channel to the targeted channel. You are not adding or subtracting colors to a specific color component as you do with the Selective Color adjustment.

Channel Mixer presets are available from the Preset menu in the Adjustments panel. Use the default Channel Mixer presets to create, save, and load custom presets.

Mix color channels

  1. In the Channels panel, select the composite color channel.
  2. To access the Channel Mixer adjustment, do one of the following:

    • Click the Channel Mixer icon  or a Channel Mixer preset in the Adjustments panel.

    • Choose Layer > New Adjustment Layer > Channel Mixer. Click OK in the New Layer dialog box.

    Note: You can also choose Image > Adjustments > Channel Mixer. But keep in mind that this method makes direct adjustments to the image layer and discards image information.
  3. In the Adjustments panel, choose a channel from the Output Channel menu in which to blend one or more existing channels.

    Choosing an output channel sets the source slider for that channel to 100% and all other channels to 0%. For example, choosing Red as the output channel sets the Source Channels sliders to 100% for Red, and to 0% for Green and Blue (in an RGB image).

  4. To decrease the channel’s contribution to the output channel, drag a source channel slider to the left. To increase the channel’s contribution, drag a source channel slider to the right or enter a value between ‑200% and +200% in the box. Using a negative value inverts the source channel before adding it to the output channel.

    Photoshop displays the total value of the source channels in the Total field. If the combined channel values are above 100%, Photoshop displays a warning icon next to the total.

  5. Drag the slider or enter a value for the Constant option.

    This option adjusts the grayscale value of the output channel. Negative values add more black, and positive values add more white. A ‑200% value makes the output channel black, and a +200% value makes the output channel white.

    You can save Channel Mixer dialog box settings for reuse on other images. See Save adjustment settings and Reapply adjustment settings.

Create monochrome images from RGB or CMYK images

Monochrome images display color channels as gray values. Adjust the percentage of each source channel to fine-tune the overall grayscale image.

  1. In the Channels panel, select the composite color channel.
  2. In the Adjustments panel, click the Channel Mixer icon , and then do one of the following:

    • Select Monochrome.

    • Select one of the default presets from the Channel Mixer menu:
      Black & White Infrared (RGB)
      Red=‑70%, Green=200%, Blue=‑30%

      Black & White With Blue Filter (RGB)
      Red=0%, Green=0%, Blue=100%

      Black & White With Green Filter (RGB)
      Red=0%, Green=100%, Blue=0%

      Black & White With Orange Filter (RGB)
      Red=50%, Green=50%, Blue=0%

      Black & White With Red Filter (RGB)
      Red=100%, Green=0%, Blue=0%

      Black & White With Yellow Filter (RGB)
      Red=34%, Green=66%, Blue=0%

    Note: You can also choose Image > Adjustments > Channel Mixer. But keep in mind that this method makes direct adjustments to the image layer and discards image information.
  3. To control the amount of detail and contrast in the images before you convert them to grayscale, use the source channel sliders.

    Before adjusting the percentages of the source channels, view how each source channel affects the monochrome image. For example, in RGB, view the image with the Red channel set to +100% and the Green and Blue source channels set to 0%. Then, view the image with the Green source channel set to +100% and the other two channels set to 0%. Finally, view the image with Blue source channel set to +100% and the other channels set to 0%.

    The Total value displays the total percentage of the source channels. For best results, adjust the source channels so the combined values equal 100%. If the combined values are above 100%, a warning icon appears next to the total, indicating that the processed image will be brighter than the original, possibly removing highlight detail.
  4. (Optional) Drag the slider or enter a value for the Constant option.

    This option adjusts the grayscale value of the output channel. Negative values add more black, and positive values add more white. A ‑200% value makes the output channel black; a +200% value makes the output channel white.

Create a hand-tinted appearance for specific image elements

  1. In the Channels panel, select the composite color channel.
  2. In the Adjustments panel, click the Channel Mixer icon .
  3. Select and then deselect Monochrome.
  4. Choose an Output Channel option, and adjust the source channel sliders. (Repeat this step as desired for each output channel.)
A.
Original color image

B.
Selecting Monochrome creates grayscale image

C.
Deselecting Monochrome and mixing channels tints elements of grayscale image