1. Get a shulker box

Note that at this point the shulker box doesn't have any name.

2. Rename the shulker box to anything. In this example it will be 'test'.

Note that at this point the shulker box has the name 'test'.

3. Rename the shulker box to nothing, meaning it has the default non-italic name "Purple Shulker Box". This can be done by placing the renamed shulker box into an anvil and deleting all the characters in it's name.

Note that at this point the shulker box at this point has no name.

4. Dye the shulker box to some other color.

The shulker box will get it's name back. So in this example it will get back the 'test' name.