Rainbow Blocks With Tinker Cad

This is how I made these 3D printable rainbow blocks on tinkercad

A computer

The Tinkercad website

First, put down a red block in the bottom left corner.

Then add two orange blocks on top and to the right of the first red block.

Then continue this last step with all the colors of the rainbow adding one more block each time until it is as shown above.

The last step is to continue but reverse the colors and the amount until it's finished like above.