Dear Maurizio.

'The Active' is a rose bred by Ken Nobbs. While it is sometimes given as seedling of Mutabilis, my personal experience with it makes me doubt about this information. I would say that The Active has quite a bit of sempervirens in it.
However I do not know 'Yellow Mutabilis', and, therfore can not compare.
Is it another one of P. Beales found / renamed roses?