Beets have a lot of sugar, so it might be harmful for you because it feeds candida.
I am with you when it comes to green juices. If you like lemons, you can add some. It tastes much better.
So far, my favorite juices are carrot and Granny Smith apple mixed together; orange, and red grapefruit.
I have not tried to juice other fruit because I am still on semi-anticandida diet (just one-two servings of fruit a day).
I have seen a naturopath for several reasons including candida, and he told me that it is OK to eat fruit, one serving a day, especially those that don't have a lot of sugar, like berries and apples.