[formatter] How to escape end expressions to handle JSON braces?

Is there a way to color text and escape any braces in it?

Problem: ending braces aren't getting color or they're getting removed:

hash = {wtv: 3}
CLI::UI.puts("{{magenta:#{hash}}}") # last brace is not colored
hash2 = {wtv: {key: 3}}
CLI::UI.puts("{{magenta:#{hash2}}}") # last 2 braces are missing: "{wtv: {key: 3"

Here's one work-around I found:

CLI::UI.puts("#{CLI::UI::Color::MAGENTA.code}#{hash}", format: false)

Update: The work-around isn't as easy to do for command formatting, unless you wanna assume that commands are always cyan:

CLI::UI.puts("{{command:run { {json}}}}") # omits the ending "}}"
CLI::UI.puts("\e[#{CLI::UI::Formatter::SGR_MAP['command']}mrun { {json}}", format: false) # works

Update 2:
Using colorize also helps.

Start at CLI::UI.puts and reproduce the formatter behavior with the hash and command examples in the issue. Trace how end expressions are parsed and determine how literal braces should be escaped or preserved; done means the closing braces remain present and receive the intended color.