As well as the answer I gave in the question @Catija referred to in her comment, I suspect you are not beating your meringue enough. In total you should be beating the initial meringue for a good ten or eleven minutes.
There are a lot of myths and complications around macarons. The Internet would have you believe that you must used aged egg whites from French hens, almond flour with grains individually measured for the correct size, and a hundred other things. It's mostly nonsense. Use this recipe, follow it exactly, and you will be much closer to success without all the fuss.
In my experience the three critical factors are:
- beat the meringue sufficiently. It should be super-stiff.
- macaronage correctly - this is the trickiest part, but the description of the correct consistency in the recipe I linked is a good one.
- ensure your oven dial is accurate with an oven thermometer. It almost certainly isn't.
- use powdered food colouring. Gel food colours are intended for use in icing and are not oven safe. They brown at relatively low temperatures and ruin the appearance of your macarons.
Good luck.