With Molla, you can showing more than one product images with color, please follow this instruction.
Enter Size & Color for Variant section:
+ Size: 38, 39, 40
+ Color: Brown, White, Black
If you select Swatch color
When you select a color, the image will display similar with that color.
If you select Swatch image
When you select an variant image, the product image will display similar with that variant
Hope you success!!