Thank you for responding Frank.
In my experience / understanding, I have owned countless thousands of aniline stamps, I have always believed they were the "water soluble" purple / magenta issues of most countries.
Not based on fact, just my rudimentary understanding.
I just went to "Askphil" and their notes read:
Aniline ink: a water-soluble ink which fluoresces under ultraviolet light; such as used on Roosevelt Small Die Proofs.
I had never come across an aniline brown, I was presuming is was then, water soluble brown, which appeared strange to me.
Most striking anilines, as I understand it, are the KGVl Malay states
You may have owned one of these Frank.