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# Colour Blend Node

Use Colour Blend (CBlend) nodes to set up the colour operations you want to perform on a clip. You can:

- Use the Front pipe of a layer to adjust the colour of a clip.
- Use the Matte pipe of a layer to isolate a region of the image to which the colour adjustments will be applied. With no matte, the colour correction is applied to the entire image.
- Blend the front and back images for each layer.
- Create layers of colour corrections for your front clip.

How the CBlend Node Works

The Front pipe of the CBlend node is designed to result in a colour image. This is represented visually by a red box at the right of the Front pipe. You can place any node on the Front pipe that results in a colour image. These include the Colour Curves, Colour Correct, RGB Blur, Degrain, and Regrain nodes.

The Matte pipe is designed to result in a matte. This is represented by a blue box at the right of the pipe. You can add any node that results in a matte to the Matte pipe, including the MasterK, 2D Histogram, GMask, Edge and Degrain nodes.

The Front and Matte pipes of the CBlend node constitute one layer.

(a) The two pipes constitute one layer(b) Front pipe(c) Matte pipe(d) Red box of Front pipe(e) Blue box of Matte pipe

NoteThe Degrain node results in a colour image; however, it is often useful to place it on the Matte pipe before the MasterK node (which uses a colour image for its input). For this purpose, it can be placed on the Matte pipe.

The two pipes together, along with a back component, constitute one layer. For the first (bottom) layer, the CBlend node uses the source input image for the back component. For example, in the CBlend node on the Front branch of the default pipeline, the Front clip is used for the back component. To learn how subsequent layers are composited, see Using Several Layers in a Blend Node.