How to edit other properties of a system message with TextChatService

Im using the new TextChatService, and I’m making a system message and wondering how to I change other properties besides the text, here is the line im running,

game.TextChatService.TextChannels.RBXGeneral:DisplaySystemMessage("Hello", "SystemMessage")

i want to at least change the color and size of the message without forking, im not very familiar with the documentation style of so if i should use a different method/function please let me know!