It took a while, but I recreated what the chatlog formats would look like for each rank since the forums colored chat unfortunately just doesn't properly match what it looks like in the game. The following is what each standard player rank would look like:

In an extremely odd regular day, this is what the chatlog might look like if I was on a political rampage:

Based off of the suggested chat, my personal suggestions are:
- Change the "official meeper" messages to gray - they clutter the chatlog with yellow and make it harder to read the yellow staff member chat.
- Highlight the ClearLag warnings of some sort. Changing the "Warning" label or the number of seconds left to red/dark_red would help players to see this message and avoid dropping items, even if the red color was only on the 20 seconds warning.
- Change the standard Meep-Shouts to gray. This will further reduce the clutter of yellow in the chatlog which will make staff member messages much more noticeable; this will be especially necessary if Mod chat will be changed to yellow.
- Use the first color method. In my opinion, a yellow rank tag combined with a yellow chatlog text color simply doesn't look well combined.
If said suggestions were to be applied, the chatlog would look like this:

[EDIT 1] Edited as to make the multi-line player text indented as it normally is on Meepcraft (when it works) :P