OK, I've found the issue with position/size.
When a generic posture / custom tool is added manually, there is some code that scales it relatively to the image size, to give it a sensible size.
Unfortunately, the same bit of code is also run when the tool comes from a KVA, even though it has already been positioned and sized manually.
This impacts all custom tools, flipped or not. Simply saving and reloading will provoke a change in position and size. The more the image size is different from 800x600 (the reference canvas size for custom tools) the more this will be apparent.
(Fixed in dev version)
The fact that you loose the color still eludes me. I can open your KVA fine and the tool is green.
