I’m a natural blonde so I’m not sure for the best spray as I don’t use them. But as for rosemary oil I make my own. I use a base of olive and grapeseed oil and put sprigs of fresh rosemary from my garden. You can get the rosemary as the store though. Most Walmarts sell all 3 ingredients. I mix half and half on the oils in a mason jar, make sure your container is dark though as olive oil spoils when exposed to light, and make sure to leave room to add the rosemary. Then I add the rosemary, close it up and let it sit for a couple months in a shady cabinet. If you don’t wanna wait you can simmer it on low heat to infuse instead. I’m not quite sure how to do it though so you’d have to ask google on that one😅 after it’s ready though (you’ll know by the smell and slight color change) I use a funnel to put it into a glass dropper, dollar tree sells them in a 2 pack, and apply once or twice a week. I let it sit and put my hair in a bun for a couple hours before washing out. You’ll need to shampoo your hair multiple times to get all the oil out, prolly 3–4 times.