Ue4 fail to properly export texture.

Hi, its correct, the red and blue are switched. The way to fix it in GIMP is the following:

  1. Open the image which you see in wrong color
  2. Use Colors → Components → Decompose (this will create a new image, with the 3 channels are layers instead of channels, so you can manipulate those)
  3. Duplicate the blue layer into a new layer
  4. select the red layer , select all and copy
  5. now select the blue layer, and paste the red one you copied, click on the ANCHOR to avoid making a new layer, or it will not work
  6. now select the duplicate blue and copy its content into the red one
  7. delete the blue copy layer
  8. Use Colors → Components → Recompose , this will modify the original image

You cannot change layers, but you need to paste anchor on them. Good luck.