Teach children about shape, color, and color mixing with the Constructive Playthings Color Mixing Blocks. This set of 24 blocks come in 6 different shapes for exploring geometric properties. When the four translucent colors of these wooden blocks are stacked on top of one another, new colors are made as the light reflects through. Great for stacking and imaginative play! Constructive Playthings is committed to providing safe, compliant products and a healthy, safe working environment worldwide. We require that all products meet all applicable federal regulations, which we review on a continuous basis