Green Light: Oh gosh, found someone that able to draw your attention or someone that you would like to give a try on relationship? At the very beginning, there's no harm to give a try... So just go ahead!
Yellow Light: For sure the early stage can be super sweet, lovely and romantic. After quite some time, sweetness or loveliness, you might be able to feel they are no longer that concentrate any more. Example; Less message, less call, shorter text, or even chance to meet is lesser by explaining to you there're busy! If after quite some time they still remain as before, then, congratulations! =)
Red Light: There's few possibility at this stage such as, they will be telling you to remain dating but not into relationship yet because not ready for commitment or even at the moment they don't wish to have commitment OR by telling they feel quite comfortable happy now and hope to remain it like this! Well, if this happened, don't be silly, go for new one!