Follow the instructions below on How to create product attributes and variations in PrestaShop 1.7?
First of all, open your PrestaShop dashboard. On the left side choose our catalog section and click on the Attributes & Features button.
Now we have to add the color attributes. So simply click on the add new attribute button.
Here we have to add the attribute name public name and select your attribute type. And simply click on the Save button.
Now Select attributes here that we Have selected earlier. Now simply click on the add new Value button.
So here first of all select your group type and Value Its Mean color’s name. Here you can select your color. Then click on the Save button. Add The Other attributes in The Same Way.
The next Step add the attributes in the product
Now Select The Product. Now select the product in which you add the attributes. In The Right Side, You Have To Click on a Product with combinations.
Then click on the combinations Button.
Now Here you have To select your size color and dimension according to your product. Now Click on The Generate Button. And Then Simply click on the Save button.
Let's see if our variations are added or not. Now you can see your variations have been added successfully.