Is it possible to get from an RGB input (whether it is an attribute rgb or a texture) the single lowest/highest value of each R, G, B components in the Material context? This would be similar to using attribute promote sop with the Promotion method set to minimum/maximum.
The min/max vops expect another input to compare the values with, similar to the min()/max() vex functions which is not what I am looking for. I have also tried with OSL but found the same issues with the min()/mix() functions.
This would be ideally used inside an arnoldbuilder so the nodes available are limited.

This is a limitation I have encountered frequently and it would be very awesome to know any solution if it exist.

Thanks!

I don't think there's any way to do this in the material context but in the past I have looked up rgb values from a texture on a grid in SOPs and used the attrib promote workflow...