How to turn off Launchpad transparent
You can enter the following commands in Terminal.app, they will turn off the relevant animations:

# showing and hiding Launchpad
defaults write com.apple.dock springboard-show-duration -float 0
defaults write com.apple.dock springboard-hide-duration -float 0

# changing pages in Launchpad
defaults write com.apple.dock springboard-page-duration -float 0

# restart Dock
killall Dock


There are quite a few other animations you can turn off as wel. Take a look at this answer or you could use TinkerTool

To turn the animations back on, you enter the same commands, but with 1 instead of 0