Albinism/albino in plants mean lacking chlorophylls. Regarding the flower itself, I wonder if some people use different terms to describe the same phenomenon? I ask because it gets confusing.
By the way, album micranthum flowers are rarely pure white but with greenish yellow on the petals as well as on the dorsal sepal.
Does anyone know if it's carotinoid alone or a combination of carotinoid and chlorophylls responsible for the color on the album form of the species?
Albino plants lack anthocyanin (red pigment), which not only provides red colouring, but also contributes to black spots, stripes, etc. Albino plants can have colouring from carotinoid (contributing to yellow/yellowish colouring) and/or chlorophyll (contributing to green/greenish colouring).
Botanically, album strictly means white, i. e. plants with flowers, that don't present themselves with any of the above mentioned pigments.
What makes the whole hullabaloo really confusing is, that plants with flowers, that weren't all white, back in time were first described and published as album - plants, that today would be described as f.ex. alboviride (white-green) or alboflavum (white-yellow), and for some reason, such a name, if legitimally published, seems very difficult to change (I can't explain why, but I'm sure that a botanist well versed in the International Code of Botanical Nomenclature would be able to provide us with useful input).
If it's the concept of albinism as such, that creates havoc, Gruss in his book on albino Paphs, and Braem in the 2nd ed. of his monography on the Genus Paphiopedilum, both provide a clear and easily understandable (and almost identical) chapter on the matter!