I blend my scents all the time. Those are my most popular scents. I have a Son of a Biscuit, Summer's Essience, Bermuda Triangle and more. It is easy. Once you get the hang of it, it can become addictive.
This is what you do. You have to figure out your base scent. That is the most prominent scent. Then get complimentary scents that will go well with the base fragrance. I do mine by percentage. So take for instance, you want a pina-colada scent. That smells like what. I think it has some pineapple and coconut notes. But don't forget the alcohol or the rum. The most prominent smell is coconut but coconut has a tendency to overpower so for me I would probably start off with pineapple and coconut half and half. You might have to lwer the coconut or add more pineapple. Let is sit for a day or two. See if that is the smell you want. If not, adjust the ratio. If it is good, then start adding the rum scent in .05 oz at a time till you get the aroma that is pleasing to your nostrils. You will have to let it cure because, the scent will change over time.
I hope this helped. The majority of my scents are blends because at time I have a hard time finding the right scent that I want. I have an idea of what I want it to smell like so i figure it out from there. I have made my own Peach Bellini and Rainbow Sherbet. I have never smelled those two scents in my life but everyone says it smells like the real thing.
For colour, I use liquid dye. In my opinion, liquid dye allows you to get more vibrant colours, a variety of colour options for you colour palette. It also allows you to achieve the same color over and over. Also a little goes a long way. If you add too much chips or blocks you may have a candle that is not burning properly or a clogged wick. I wouldn't use micas in a candle but it is great for wax melts. I will only use for candle if you are decorating the candle with it. I have been mica obsessed lately. I love the stuff.