Visual Studio 2017 themes
Source code - Visual Studio 2017 Themes
Dark themes with fadein & fadeout (Dark-Blue)
Source code - Dark Themes with fadein & fadeout
Dark Themes with fadein & fadeout And Dropdown arrow
Source code - Dark Themes with fadein & fadeout
To create a custom theme, you should pick up a theme then edit it. Menu provides many state class as "FIRST" "ACTIVE" "OUT".