How to lookup a value in one column to create a comma separated list

Here is a problem i often have and have never been able to figure out an answer to. Hoping someone here has run into the same problem and can help me out

I have a big spreadsheet of data. Column 1 has the item number, Column 2 has the sku number and Column 3 has the color

What im trying to do is create a comma separated list of values in a new column that would list all the colors of that specific Item No

Here is a preview of what the spreadsheet may look like

Column 1 Column 2 Column 3 ColorList
Item1 Item1-Bk Black Black, Blue Green (this is what im trying to accomplish)
Item1 Item1-Bl Blue
Item1 Item1-Gr Green
Item2 Item2-Bk Black
Item2 Item2-Bl Blue
Item2 Item2-Gr Green

Attach a sample workbook (not a picture!). Make sure there is just enough data to demonstrate your need. Include a BEFORE sheet and an AFTER sheet in the workbook if needed to show the process you're trying to complete or automate. Make sure your desired results are shown, mock them up manually if necessary.

Remember to desensitize the data.

Click on GO ADVANCED and then scroll down to Manage Attachments to open the upload window.

here is what i hope is a sample wookbook

Thanks @GC Excel

That macro works perfect

Hey is there anything you could do in this macro to remove duplicate values for each sku. For example is SKU001 has the values of Blue, Blue, Black, Brown, is there a way to make it so it would only list Blue, Black, Brown?