We have found a replacement tee supplier who does XLs (although, confusingly, their XL is more like our L and their 3XL is about what our XL should be...don't worry there'll be a sizing chart).
The yellow is not QUITE the Banana we all love, but is more like the background colour on the website. Slightly deeper without being a gold/daisy colour.
Think they'll do well.
I wandered into Lambton Quay Ryos and got myself a Rieralucion one while I was down for the day yesterday. Was distressed to find myself needing a 5XL!!! Excuse me while I find a tall building to throw myself off... :-)