The Bug

When editing a sign that uses e.g. a custom color, or other formatting like bold or italic text, when editing such a sign, the formatting is preserved when saving, but the preview renders it without the formatting

The changelog of 23w14a also states "Signs with non-text chat components can no longer be edited", tho it's not quite clear if this refers to signs with any kind of formatting not being supposed to be editable, or if it just means that signs that have a different string-source like a translate element are excluded.

Reproduction

1. /setblock ~ ~ ~ minecraft:warped_sign{front_text:{messages:['{"text":"test","bold":true,"color":"#8eedeb"}','{"text":"test","color":"#8eedeb"}','{"text":"test","italic":true,"color":"#8eedeb"}','{"text":"test","obfuscated":true,"color":"#8eedeb"}']}}
2. Right click the sign
   -> The text shows in black without formatting
3. Edit some text
4. Click done
   -> Text shows with formatting again

Observed Result

While editing the sign, the preview does not show the formatting, and any edited line will show unformatted on the actual sign while the dialog is still open.

For bold formatting, it is also possible to add more text than fits the sign.

After confirming with "Done", the correct formatting is applied again.

Expected Result

Either:The sign always shows the correct formatting;
Or: it's impossible to edit such a sign.