Okay, first (and I say this because "I" am usually guilty of it!), IF(?) we are to discuss this by 5th ed RAW, it's important to shake off any preconceptions from earlier editions, especially about what a Ritual is and does. It no longer has anything to do with permanence, necessarily (See p81 "Ritual Magic", and etc.)
Under The Limit of Essential Nature (p 79), it explicitly states..."Any magic which violates a thing's essential nature must be maintained, and when power is no longer supplied the thing returns to its natural state. Thus, Muto magic must always be maintained..."
(I don't like that word "thus", because Muto and breaking Essential Nature do not always go hand in hand.)
However, it goes on to raise the issue of what, exactly, is "Essential Nature" and what is not..."A thing's essential nature varies depending on what it is. All human beings are essentially human... The basic shape of a human body is also part of the essential nature, tho' bits can be cut off..."So, the question in your specific example would be- "Is a rose's color part of its essential nature?"
This was brought up tangentially in another thread. Is skin color is part of a human's essential nature, or fur color part of a beast's? If my mage wants a bright red hound or truly blue horse, can they make that a permanent change? What if the color is within the "natural" spectrum, even if not natural for that breed? What if it mimics the color of a (similar?) animal, or exaggerates that color? (A fox is close to red, and I've seen very blue-grey dogs...)
It's clear that, in 5th, you can't change an animal into a human (or vice versa) for longer than a year, because that IS, specifically, part of their essential nature. Other changes are variable, depending on that E.N., and that, ultimately, is up to each Story Guide and Troupe.
Now, for me, the classic "permanent mark" from an angry mage is very in-genre, and a scar or brand or birthmark added to a human target is just too traditional (imo) to be deemed "against EN". This could possibly run even changing their skin-color to bright blue, altho' that might starting to push it for some- or not.
Now, if you change one thing "permanantly", does it then breed that trait? Ugh... that does sound more like the realm of "Essential Nature"- tho' it is also a classic bit that should not be ruled out too quickly.
I think it's also fairly clear that with such a subjective (and ultimately arbitrary?) limit, that Hermetic Research should allow one to push that limit, if never remove it entirely.
Ymmv, but that seems to be how the rules read.
(So, my Vote would be... "None of the Above"*, because, imo, Muto can already be legally permanent (or should be), but only within the limits of EN)
(* I feel like I'm voting for President!)