Stop using spot metering. Unless one is a VERY serious, fastidious, near-expert user, spot metering can easily lead to a number of very serious exposure problems. ANd no, I am not kidding or teasing, in any fashion or manner. I mean this 100% sincerely.
You do not mention what camera you are using. Modern Nikons, and a few of the very-newest Canon cameras, can read BOTH reflectivity AND color of subjects, and are NOT color-blind and "dumb", like older light metering systems. SOme people have tried to blend the old "roll-film modified Zone System concepts" of adding or subtracting exposure, AS IF they were using an old, "dumb" (dumb as in color-blind) 1960's era spot meter calibrated to 12% to 18% gray. And guess what? They have a lot of problems.
I honestly think that spot metering leads to more problems than solutions, unless the user is an expert photographer, and is intimately "dialed in" to EXACTLY how his camera works, with his entire system of metering, processing, and his own equipment set-up.