Mix shiratamako, joshinko, and sugar. Set aside.
Whisk silken tofu until all large clumps have broken apart and the mixture looks more like liquid. Add tofu to your dry ingredients in small increments until your dough comes together in a ball and is about the texture of play dough. It should be squishy but not stick to your hand. If it's too dry, add more tofu. If it's too wet, add more of the rice flours.
Split dough into three equal sections.
Add a drop of green food coloring to one section and a drop of red food coloring to another section. Knead to disperse the color. If using matcha and freeze dried strawberry powder instead, simply add each to your section of dough and knead until the color is all worked through.
Split each of three sections of dough into eight balls, rolling them in your hand. They should be about a teaspoon each or roughly 15g.
Bring a large pot of water to boil and gently place all the dango in the pot. When the balls start to float in the boiling water, they are almost done. Let them cook for another minute before fishing them out. Note: Some other recipes advise cooking the dango in stages according to color to avoid the dyed dango bleeding onto the white ones, but I've never had an issue.
Let the dango cool until you can handle them with your hands. Stick them onto skewers with green first, then white, then pink.
Dango are best enjoyed fresh but can be kept in an airtight container in the fridge. If eating leftovers, I like to microwave my dango for a few seconds to soften them back up. Enjoy!