In 2009, I made a black and white nautical flags set called Foxtrot Sierra. I finally got around to revisiting it with color. I've made a number of refinements to the Foxtrot Sierra design beyond just adding color. One note, the numbers should be pennants, but I decided to stick with my wider rectangle for this font.  

(Foxtrot Sierra is FS in the NATO alphabet for FontStruct. Charlie is C for color.)

I have made a font with International Maritime Signal Flags before, but this time they are coloured correctly (in grey scale). White is blank (  ), yellow is little dots (::), red is 33% diagonals (\\), blue is 50% diagonals (//), black is filled. Lower case letters are the patterns with no colouring, for those who want to colour in the fields themselves.

I have now added numbers. The regular numerals (0-9) are the square NATO flags, and the subscript numerals (₀₋₉) are the templates of the NATO number flags. The roman numerals (I-X, X representing 0) are the longer ICS flags, and the lower case roman numerals (i-x) are the uncoloured ICS flags.

On top of that there are four substitute flags, which can be found in the superscript numbers (¹⁻⁴) and the fifth fractions (⅕-⅘).