I'm a child of the 70s and when I saw a yellow submarine tea infuser while browsing the web it brought a smile to my face as I thought of a favourite childhood toy. That childhood toy was a metal yellow submarine so not so good for brewing tea, although back then I probably didn't like a nice cuppa as much as I do today!
I still have my old metal yellow submarine too, somewhere. I'm sure I have. Even though I've been unpacking boxes I haven't unpacked that yet. I know it was a well loved and well played with so it's unlikely to be of any monetary value as while it's not in OK condition, it's not pristine. The value for me is in my memories, so all together now...
"In the town where I was born, lived a man who sailed to sea, and he told us of his life, in the land of submarines...
...We all live in a Yellow Submarine, a Yellow Submarine, Yellow Submarine...."