There are many ways in which these names can be used as colors. Probably the most common, as you said, is along the lines of the cereza color bicicleta for “the cherry-colored bike.” This is brief for the color bicicleta of cereza. Saying bicicleta cereza is one way to shorten it even further. The logic of las bicicletas cereza for “cherry-coloured bikes” is that we use an abbreviated form of cereza-colored bicicletas. Or at least, it might be a simpler way to think about it than to think of Cereza as an immutable adjective. Even if you start your adventure with the Spanish language, you probably already know that names and adjectives must correspond in terms of gender and number. Everybody does it. This means that regardless of gender or main number, color and adjective/nomene remain in the male singular form! The adjectives of nationality that end in -o, z.B. Chino, Argentino follow the same patterns as in the table above. Some adjectives of nationality end up in a consonant, z.B, espaol and alemén, and they follow a slightly different pattern: if you look at an adjective in the dictionary, it`s always in the male singular form, for example. B blanco. Spanish adjectives usually follow the patterns of this table to match the nameinus they describe.
In Spanish, the tendency to name colors for other objects is even more common, and the grammar rules for these object adjectives differ from other adjectives. But what can happen over time is that a noun used in this way can be considered an adjective, and once it is considered an adjective, it will probably change the form for the plural (and possibly the sex). In Latin America in particular, some of these words (especially Naranja, Rosa and Violeta) are treated as typical adjectives that change in number. So it would be fair to refer to los coches naranjas. (It should be noted that in some areas, the anaranjado adjective is also commonly used for “orange”). But don`t worry too much, because most of the time, colors just act as they should: as descriptive adjectives. As mentioned above, Macho and Hembra are probably the traditionally immutable adjectives (although you will often hear them in the plural, perhaps more often than ever).