Sigma Logo

"Simple is not always attractive". What do you think about this design. Honestly I'm not satisfied with this. Its Not eye catchy for me. Can you help with this design. I'll be very pleased if you have a better idea willing to share.
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colors will be same.
must reflect something square shape.
play with letter S not just simple S. something that show a little imagery of S.
email: hiisumir@gmail.com