Some fine designs, but you'll need to keep the following points in mind:
* You'll want to avoid pure, fully saturated colors. Pure black isn't possible to achieve in nature

Try a black around RGB 50, 40, 30 instead.
* For the sail, you'll need to remove the textures and use a transparent background instead. Decals and sails can be colored separately in-game. If your design covers about 50% of the sail or more, you'll also want to make it partly transparent, e.g. with an opacity betweeo 50-70%, so some of the underlying sail texture shows through.
* Text on flags is perfectly fine, though as noted, it will always appear backwards half the time, no matter what you do.
Looking forward to your next revisions
