You cannot turn off the German text. It is what it is. That was one of the reasons for the making of
Fall of the Rising Sun Ultimate (FotRSU). It was originally just going to be a translation and clean-up of the run-a-way spawns, but we ended up taking all of AOTD_MadMax's FOTRS versions and putting them together, along with additional ships and airplanes, and calling it "Ultimate". But it is for SH4 vf1.5 only...
The colors in FOTRS v2 just seem to "pop" though, don't they, especially at night? You could open the "menu.txt" file found in the "Data / Menu" folder of the mod, and run it through a translator. Since the translators can be rather cryptic in their translation, it can still be a bit difficult to understand the translated text. Be sure and make a copy of the file before you copy the translated version back into that same folder. Such, as rename the original file "menuBAK.txt" or some such, then name your new file "menu.txt" in that same folder, and see how it turns out. If it bombs, delete your translation, and rename the other back. btw, v2.0 of FOTRS is for SH4 v1.4 only, so that's what you are using, correct?