Hot take: I wasted a full day trying to match a specific shade of blue from a photo
Client sent a reference image and said 'just get the blue right'... sounded easy. I spent 4 hours in Photoshop just sampling and adjusting, but the print proof looked totally wrong. Turns out the photo was taken under warm indoor light, so the actual color was a cooler cyan. Had to find the original object and scan it, which took another 3 hours. Anyone else get completely derailed by bad reference images?
A solid color calibration card is worth the investment. You can pick one up for like fifteen bucks and it saves hours of guesswork. I keep one in my bag and take a quick reference shot before anything else. Solves the whole "is this pink or neon" debate before it starts.