Sweden for the light blue one?
It shouldn't be that
light, and anyway, the only bit of yellow we see there (apart from the trimming) is more like gold with blue, nonparallel trimmings. There's no national flag like that.
It's quite possible that a special "Starfleet flag" or "Federation flag" was designed and created for the show at this point, and that the Cuban flag was introduced for symmetry and additional decor, forcing TPTB to hide the details of their expensive custom flag as well. And then it so happened that no further opportunities emerged for showing the custom flag in all its glory, and perhaps it was even lost before we got the patriotic scene in "And the Children Shall Lead"...