To make tinted glass in Minecraft, you will need four amethyst shards and one glass block placed in a crafting table, as shown by the image below.
Tinted glass is not a hard block to make, but the amethyst that is required to make the glass is hard to get. So to start, you will need to locate a geode and get the amethyst shards you need from inside of it.
You can locate these geodes in large clusters starting from Y=70 and below, and you can tell if you found a geode by the smooth basalt block outer layer.
Geode can also be found on the surface exposed in beaches or underwater in the ocean, but you will mainly find them spawning commonly underground around Y=70 and bedrock layer.
When you find the geode mine inside of it, and locate an amethyst cluster pictured below.
This is the fourth stage of the amethyst's growth cycle and the ony one where you can get a shard. Along with that, you can mine this cluster with a stone pickaxe and above.
Once you get at least four shards from geodes, you will be good to go on the shard front and will only need glass next. You can make glass by digging up sand blocks from beaches and deserts and then melting sand down inside a furnace.
When you got all of the materials made and acquired, used the pattern at the start of this guide to make tinted glass in Minecraft.