If I say "new something", does it sound weird?
That is a great question. "Some" is a quantifier, meaning it indicates quantity or volume, and quantifiers come before adjectives that come before nouns. It is a grammatical rule that they are used only in the order Quantifier + Adjective + Noun. You can't say "pink one dress", "cheap some books" or, "big few birds". Since "something" is made by combining a quantifier with a noun (some + thing), there simply isn't any room left between them for an adjective, even though technically "something" is no longer being used as a quantifier. The rule still remains the same. Put a different way, something is not a noun that can be modified by an adjective; adjectives modifying it are phrases and must come after the word "something" and not before it. You can say "some new thing" or "some thing (that is) new" or "something (that is) new." Ex: I need something new for the party. Ex: Let's try something new.