That's a perfectly reasonable way to conceptualize potions in your game, but as you've quoted, it's directly at odds with how TSR D&D describes potions. Not just the passage from B/X, but, how the 1E DMG describes them:
page 125:
"Potions are typically found in ceramic, crystal, glass, or metal flasks in enough quantity to provide one person with one complete dose so as to be able to achieve the effects which are given hereafter for each type of potion. Potion containers can be other than as described at your option. As a general rule they should bear no identifying marks, so that the players must sample from each container in order to determine the nature of the liquid. However, even a small taste should suffice to identify a potion in some way- even if just a slight urge. As Dungeon Master you should adda few different sorts of potions, both helpful and harmful, of such nature as to cause difficulties in identification. In addition, the same type of potion, when derived from different sources, might smell, taste, and look differently."
page 119:
"While it is possible to prepare a matrix which lists each potion type and cross references each to show a certain result when one is intermingled with the other, such a graph has two drawbacks. First, it does not allow for differences in formulae from alchemist and/or magic-user. Second, it will require continual addition as new potion types are added to the campaign."
Emphasis mine.
Gary and Tom were both clear that potions vary, and you can't rely on just recognizing it by appearance or smell without sampling it and taking the risk that it's poison.
While we're at it, here's the 2E DMG, p 141:
"Identifying Potions
As a general rule, potion containers should bear no identifying marks, so player characters must sample from each container to determine the nature of the liquid inside. However, even a small taste should suffice to identify a potion in some way. Introduce different sorts of potions, both helpful and harmful, to cause difficulties in identification. In addition, the same type of potion, when created in different labs, might smell, taste, and look differently."