I was creating a module that allows you to easily create chat tags and such but I realized when you specify a stroke in a chat message (ie using the stroke tag), the stroke does not fade out while the rest of the chat does, leaving only an outline:
As @bvetterdays mentioned, this is an issue related to TextTransparency, it isn’t exclusive to the TextChatService:
Repro steps
1- Add a stroke to a TextChatService message using TextChatService.OnIncomingMessage.
2- Send a message and wait for the chat to fade out completely
3- Observe that the stroke remains while the rest of the text does not.
All jokes aside, I can confirm this is an issue and definitely should be addressed. I assume it is because it has the same behaviour as the text-based GUI elements and Roblox forgot.
This is an issue with RichText as a whole, not just the chat. My game has been plagued by this issue for a while but have never gotten around to filing a bug report.
As a workaround you can save as attribute original text with rich text strokes, and then when tweening use string.match to replace transparency with 0-1 values based off text transparency.