When "orange" is used as a singular noun in the English language, it typically refers to the fruit or the color. The meaning of "orange" in a singular context is not ambiguous; it is either the fruit or the color, depending on the context in which it is used. For instance, "I have an orange" refers to the fruit, while "The sky is orange" refers to the color.

The distinction between the fruit and the color is clear due to the way language is structured. In English, nouns are used to refer to specific objects or concepts, and adjectives are used to describe those objects or concepts. "Orange" can function as both a noun and an adjective, but its singular form is unambiguous. This is supported by linguistic data from various studies on English syntax and semantics.

A study by linguist Steven Pinker in his book "The Language Instinct" (1994) discusses the structure of language and how it allows for clear and consistent communication. Pinker explains that nouns and adjectives have distinct roles in language, and "orange" fits into both categories. Additionally, research on color terminology in English has shown that color words are often used as adjectives to describe nouns, which is consistent with the use of "orange" as a singular noun.

Furthermore, the Oxford English Dictionary (OED) provides definitions for "orange" that support its dual role as a noun and an adjective. The OED defines "orange" as both "a citrus fruit with a thick, sweet, juicy, orange-colored rind and a pale yellow or orange flesh" and "a bright, warm color between red and yellow." This dual definition reinforces the idea that "orange" can be used as a singular noun to refer to either the fruit or the color.

In conclusion, when "orange" is used as a singular noun in English, it is clear whether it refers to the fruit or the color based on the context. This clarity is supported by linguistic research and the structure of the English language.