Autumn is the perfect time to switch up your hair colour.

During summer, we spend so much time out in the sun that any colour is bound to fade a little, meaning you basically threw money out the window. In other words, you'd be far better saving your appointment with the colourist for autumn – and when you book it, you are going to want to know about this colour trend – especially if you are a brunette. You are familiar with the beverage, but what the heck is cold brew hair, you may wonder? Well, according to L'oréal, cold brew hair is called so because it simply mimics the beautiful colour blends that occur when you mix coffee with a splash of milk and ice. The best bit? The look is totally customizable—just like your coffee. "If you drink your coffee black, your cold brew is likely darker, mixed with reddish hues from melted ice. If you take your coffee with lots of milk and sugar, your cold brew will surely be light and sweet. It’s up to you which shade of cold brew you take your hair colour inspiration from." And while it can be tempting to DIY the colour to save yourself some money, the colourists at L'oréal are keen to remind us that this hair colour may be best done by a professional, as a trained eye will be able to expertly place highlights and lowlights to create your ultimate cold brew hue, not to mention, they can let you know if the shade you want will work for your skin tone. Speaking to Allure magazine about the trend, colourist Nikki Ferrara says she is a huge fan of the warm brunette shade. "This is great for people with dark hair that would love to dip their toes into being a redhead without too much of the commitment — or for women who still want warm tones in their medium brown hair." These locks look like our iced coffee after we pour in a splash of almond milk and watch it slowly melt its way down. The deliciously rich ombré finish is just what we ordered. Sound enticing? We know! And if you are looking for inspiration, we found tons on Pinterest, and under the hashtag #coldbrewhair on Instagram.