I spy the color blue!

I used to host regularly and haven’t been swapping in a few years but I’m back! This time I’m doing a flat mail swap based around the color blue! Fill a regular envelope with blue items, this can be post cards stickers, notecards, handmade envelopes, or whatever can fit into the envelope and is blue! Please include at least five decently sized items. If stickers, about palm sized count as one, or a sheet of stickers.