It's not very clear cut. Usually they'll go after, I'd say around 80% of the time. Sometimes basic adjectives can go before the noun, such as "petit" (small) and "grand" (big). And adjectives with function rather than a descriptive purpose would go before, such as "plusieurs" (several). And they can go before the noun for emphasis, such as the word "sale" meaning unpleasant or dirty. Colour adjectives and adjectives denoting shape however, will always come afterwards.
I feel like I'm too far into French to be asking this, but how would you say something like the red, round apple? Would it be "la pomme rouge et ronde," "la pomme rouge ronde," or something like "la pomme est rouge et ronde"?
If the two adjectives are ones which follow the noun, separate them with "et", i.e., la pomme ronde et rouge. Sometimes one may be a BANGS adjective and the other not, in which case: le grosse pomme rouge. https://www.thoughtco.com/introduction-to-french-adjectives-1368789