Is my vitamin C dead? It went kind of orange

My L-ascorbic acid serum was a pale straw color when I bought it maybe four months ago and now it is distinctly orange, heading toward amber. It does not smell off exactly, and it still absorbs fine. From what I understand this means it has oxidized and lost potency, so it is not harmful, just weaker. My questions for the group: do you toss it at the first color change, or use it up since it is not dangerous? And has anyone found packaging that genuinely extends the life of these? I keep mine in the bathroom cabinet, out of direct light, but I am wondering if the humidity from showers is speeding this up and I should move it somewhere else entirely. Feels like I am pouring money down the drain every few months.