Magento is an open-source e-commerce platform. It is one of the most popular open e-commerce systems,where You can Create your own ecommerce store.
Magento Store have several option to add products.There are several option of Simple Product types like Simple Product , Grouped Product , Configurable Product , Virtual Product , Bundle Product and Downloadable Product.
Configurable products in a Magento store need several assigned attributes such as size, color, model, make, etc. You need dedicated server for configurable product.
There are few basic steps involved in the creation of a Magento Attribute for Creating a configurable product:
- Log in to your Magento admin panel
- Select the “Catalog” tab
- Go to Manage Attribute
- Add attributes (such as color and size etc.).
Shown in the image how to add attribute

There is option in ADD ATTRIBUTE in right of magento panel.
Keep in mind few things that scope is always Global, Catalog Input Type for Store Owner to Dropdown, Values Required to Yes and Choose Yes option from the drop-down menu of Use to Create Configurable Product.
Next step is Go to the click Manage Label / Options at left of your admin panel

Manage option(value of your attribute) where you can see
In Admin you fill color name as seen in above image,in position which color you want above.

Now to Add Attribute Set
- Select the “Catalog” tab
- Go to Manage Attribute Sets

Just drag both the color and warranty attributes into the left panel under the General group, and hit the Save Attribute Set button.

Add the Configurable Product
To add a Configurable Product. Go to Catalog > Manage Products and tap the Add Product button. and select Configurable Product from the Product Type drop-down.
Select both of the attributes i.e. Color and Size
Then fill up the form steps are below:-
General infomation like name, Description, Short Description SKU , Status etc. SKU should be unique and Status should Enabled.

2. Then add price of the product and first Price(MRP), special price(Sale or Your price) and Tax class select the option as per the product.

3.Then Select the inventory and select the option in stock

4.Select the Category. then click to Save and Continue Edit.
NOTE: AFTER DOING THE ABOVE STEP THEN UPLOAD THE IMAGE

After uploading the image the click to ASSOCIATED PRODUCTS

Fill the Form click Status should in enabled, visibility Not Visible Individually , select Color,Size and Qty.
Then click to save button