I don't know about fresh flowers but I used dried hibiscus and after an hour or so the water turned red. It was so pretty! You can kind of see some little whisps of red floating around the petals in the picture below.
To bring love and attention your way all day.
Take two slips of paper and draw a yellow crocus on one and a yellow rose on the other. On the back draw this symbol.
Put one in each shoe. Eat a piece of chocolate to sweeten your breath and rub cinnamon into your skin. Before leaving the house say this three times, "Freya, the lover's friend, I ask these flowers my love to send."
I originally got this from a different website of a woman named Cassandra Eason after a Google search and I switched some stuff up to cater it more to my beliefs. I would like to point out that if you are allergic to anything listed above like cinnamon or chocolate you can absolutely substitute it with something else that would fit. Maybe there is a specific perfume that makes you feel pretty or whatever. Or you can just use the original site's spell that I got this from which has no embellishments.
Another warning, be careful just slathering things into your skin if you don't know how they are going to react. I take no responsibility. All I know is I've been rubbing cinnamon into my skin when I didn't want to use perfume or oil since I was a preteen and it's worked fine for me.
I hope everyone had at least a mediocre Valentine's Day if it couldn't be great or even good.