You’re absolutely right, and this is a good catch. In English railway terminology, “semaphore” isn’t a generic word for signals, it’s a very specific subtype. Both mechanical semaphore signals and modern colour-light signals fall under the broader category of “signals,” and English speakers instinctively make that distinction. Calling everything a semaphore blurs that line and can be confusing, especially for players who know even a little about railways.
From a translation and realism standpoint, “Signal” should definitely be the default term in SimRail, with “semaphore signal” or “colour-light signal” used only when the type actually matters. That would be technically correct and more natural for English-speaking players.