You can get bombarded with tips to stay trendy, keep up with all the new styles but does it even matter to a crafter? To me it often seems when I see these articles they focus on one new item that is "hot" but I've never seen. Or this is the color of the season but I don't see it anyone I meet. Maybe I just hang out with out of touch people or maybe this hot trends really aren't so "hot" or important anyway.
I'm not saying never to update you styles, you don't want to look like you are still stuck in the 70's but for many crafters, you have a style of your own, palettes you prefer. My advise is stay true to your own self. If you make and like delicate jewelry, it doesn't matter if big chunky styles are this year's item, a market still exists for your items. I'm sure you've seen most people don't change their whole look every year. the majority of people tend to stay in their comfort zone anyway.
Purple may be the color of the year, actually I have no idea, but if you create in earth tones, do you have to revamp your whole line? There is nothing wrong with adding that new color as an accent if you want to but you just let it fit in with your own brand.
I think it's more important to have a style of your own. Discover your palette, your style, your materials. Update your line when it feels right to you. People buy handmade for that personal touch. If they just wanted trendy items, they would be in a designer store. Keep your work fresh, but keep it personal. It's your work, next year the designers will be saying something totally different but handmade isn't all about following trends, it is about setting a style of your own.