Premultiply RGB with AlphaΒΆ
The operator Premultiply RGB with Alpha can edit the color channels of images or mesh color attributes. It can multiply or unmultiply the color channels with the alpha channel.

Usage:
Execute the operator Premultiply RGB with Alpha
Select the mode
Select Premultiply or Unpremultiply
Select the image or mesh color attributes
Launch the operator Premultiply RGB with Alpha
Note
It does not edit the alpha channel.
Any color associated with 0.0 alpha cannot be unpremultiplied. In different words, assuming the alpha channel represents transparency, any color that is fully transparent will be set to 0.0 and cannot be set to its initial value when unpremultiplying color with alpha.