Might be the light blue color scheme, which is found on the flags of Micronesia, Fiji, Palau, and Tuvalu as well as a couple of communes in French Polynesia (but also Argentina, Kazakhstan, St. Lucia, and the United Nations).

I think in particular the combination of light and dark blue as is the case with the Union Jack being present on Fiji and Tuvalu.

Fiji is of particular interest as in 2015 they held a replacement competition where many (most?) of the entries had the same light and dark blue color scheme (they ended up keeping the Union Jack flag though).

Also interestingly the Ryukyu independence movement uses this color light and dark blue scheme for their proposed flag of independent Ryukyu, as does one of the proposed flags for independent Taiwan/Formosa

I was thinking the 8 pointed star was also common in the Pacific, but I found no pacific flags with it. Australia has 7 while Nauru has 12 and Marshall Islands have 24 pointed stars. It can be argued that Bouganville’s 24 triangles form a star, though it’s a stretch.