I've had a classic dark-colored coat in my wardrobe for a long time, and it never goes out of style - I wear it every season and it goes with everything. Honestly, chasing fashion trends in outerwear is risky: trends change fast, and a good coat should last several years. It's better to go for quality tailoring in a neutral color - dark shades, beige, gray - that's your foundation that won't let you down.
If you want to stay on trend, add fashionable touches like an unusual silhouette or details through accessories and the lower part of your outfit, but let the coat itself be reliable. Classic outerwear isn't boring - it's practical.