I need to make floating colored and bold text in Minecraft, but the CustomName tag doesn't have a color or bold tag (that I know of). I need a 100% sure answer.
You can't put JSON text formatting in entity names (nor in things like item names/lore). Instead, you should use the section symbol, "§", and a formatting code. E.G: §c before the name for red, §l before the name for bold.
So on Bukkit, you can do & and then put a letter / number to make things colored, but I found this list:
\u00A70 - BLACK \u00A71 - DARK BLUE \u00A72 - DARK GREEN \u00A73 - DARK AQUA \u00A74 - DARK RED \u00A75 - DARK PURPLE \u00A76 - GOLD \u00A77 - GRAY \u00A78 - DARK GRAY \u00A79 - INDIGO \u00A7a - GREEN \u00A7b - AQUA \u00A7c - RED \u00A7d - PINK \u00A7e - YELLOW \u00A7f - WHITE \u00A7k - Obfuscated \u00A7l - Bold \u00A7m - Strikethrough \u00A7n - Underline \u00A7o - Italic
Instead of putting & for colors, try these, so say you want the CustomName to be red and bold, use:
before your text.
WARNING: I have no experience using this in CustomNames, but I did accomplish my message of the day color on my vanilla server using this.