Anyone know the part number for Midnight Black Metallic touch up paint?

Attitude Black and Midnight Black Metallic are the same color.

Toyota will often rename colors in different markets to make them sound "better". But the parts system almost always uses the original Japanese name for the color(translated). In any case, your color code is 218.

Code:

Code   North American Name          Japanese Name
040    <not available>              Super White II
089    Wind Chill Pearl             Platinum White Pearl Mica
1L0    Cutting Edge Silver          Silver Metallic
1M2    Guardian Gray                Ash
218    Midnight Black Metallic      Attitude Black Mica
5C5    Maximum Yellow/Karashi       Mustard
3U5    Supersonic Red               Emotional Red II
8Q4    Reservoir Blue               Dark Blue