Take plain white rice flour or all-purpose flour as a base
Add food coloring or natural color powder to the base
Mix well until the color spreads evenly
Add a few drops of water only if needed for better mixing
Dry the mixture completely before use
Sieve the mixture to remove lumps
Use turmeric for yellow color
Use beetroot powder for pink or red color
Use spinach powder for green color
Use cocoa powder for brown color
Use blue food color for blue rangoli powder
Store each color in separate airtight containers
Keep the colors dry and free from moisture