Yuka Kibe

Let me provide some additional explanation.
The names of shulker boxes created up until now have been displayed in color. However, a new shulker box created with an anvil is displayed as having a cost and being colored, but the text color of the shulker box created is white. §o§l§b were all invalid.
Regarding signs, both previously created and newly created ones, all those that have been colored with § or dye are displayed as black text, not colored.

To this day, the letters remain black as they cannot be colored with § or dye.