Thread:NeonSpotlight/@comment-24023648-20150520141245/@comment-3308937-20150603204733

Sorry for the (extremely) late reply, my notifications weren't being updated for whatever reason. I know you can find two of the logos, one older and one newer, in your League folder.

Riot Games > League of Legends > RADs > Projects > lol_game_client > releases > 0.0.131 > deploy > data > images > SplashScreen.dds

will get you the older one

Riot Games > League of Legends > RADs > Projects > lol_game_client > releases > 0.0.0.153 > deploy > data > images > SplashScreen.dds

will get you the newer one