In Hindu philosophy, Ruparupa is the non-visibility of forms. The eyes directly see those things which have a gorm, or roopa. They are called vyakta (visible). Even those which cannot be seen have an invisible existence called avyakta. For example, atoms cannot be seen by naked eyes but still they exist. This form of existence is referred to as rooparoopa. It is only an adjective with which a thing could be associated. The existence of force in the wind is responsible for cognizance of wind through the skin. When two or three atoms cling together, there will be the production of a molecule, which will have a form.
The presence of maha makes the arupa associated with rupa. Till a body gains mahatva, it is in the ruparupa form. It is believed by some scholars that the cosmic creation started with the vyasti-srishti by the will of God, the Supreme Brahman. Then the Brahma with four heads, Chaturmukha Brahman coming out of the naval of God, created samasti srishti, where everything was visible.
The rupa is realized only in prithvi (earth), jala (water) and tejas (fire). Prithvirupa is of seven types, due to paka, and is not permanent. This may be related to the seven colors, as white is the conglomeration of seven color. Due to the combination of three colors, other colors are formed. Other than these, seven are ruparupas.
Grammatically, when one derives a word etymologically, it is called its form. When the form is changed to some other form, as per a particular context, it is referred to as ruparupa.