Added indent to arrays

I had this :
```
{
 "Fer" :  {
  "color" : [
0.296361,
0.307408,
0.331609,
1.0
  ]
 }
}
```
And wanted this :
```
{
 "Fer" :  {
  "color" : [
   0.296361,
   0.307408,
   0.331609,
   1.0
  ]
 }
}
```