If a clothing slot is set to 0, it is invisible.
Here is what I have found out about the table.
PKHeX trainer tables
row:column
1:1 nothing (dress)?
1:2 can’t edit
1:3 Hair
1:4 Front of face
1:5 torso
1:6 skirt
2:1 legs?
2:2 shoes
2:3 bag
2:4 hat accessory
2:5 none?
2:6 none
3:1
3:2
3:3
3:4
hair color data
0: black
1: dark brown
2: golden brown
3: orange/red
4: blonde
The none ones mean I couldn't find any changes, but I could be wrong.