Why is Oak grain filler Pink? =s

[Tetsuaiga]

I'm just asking out of curiosity really, I got some Rustins oak grain filler and its a pink colour.

I gave it a try and really don't like the results, but why is it pink anyway. Arn't grain fillers normally meant to be a close match unless you're after a special effect?

Is it perhaps American and intended for red oak?

 

[MIGNAL]

Try some on an off cut. Let it dry and then use your chosen finish. Some fillers will change colour when the finish hits it.
The usual rule though is that the filler should be quite a few shades darker than the actual timber. Even on walnut I go very dark Brown, verging on Black.