(SOLVED) Changing exhaust color is... broken?

I've tried changing the exhaust colors on my SV80's main engines to 00AAFF (R0 G170 B255, aka the color code for "Zenith's Glow Blue") but they don't seem to change, instead keeping the normal methalox plumes. I've tried doing this with other crafts too (since the SV80 was made before the 900 versions) but it doesn't work on those either.
It's entirely possible this is some device-specific stuff (after all, my ipad is almost 6 years old lol)
If you're wondering, all other XML options (that i've actually tried) work normally. Might make a bug report of this later, idk

Here's another pic: i've tried different formats for HEX codes (RRGGBB, rrggbb, RRGGBBAA, and rrggbbaa which i'm currently using) but all have the same result.