"Soul" is a reference to our inner selves, our spiritual selves. When we were saved God quickened our innerselves and gave us a new soul...a soul that reflects our relationship with Him. Which brings up Echo - "Echo" refers to a reflection of sound or waves in water ... it's a reflection term...so "Soul Echo" refers to us reflecting God's love and His power in our lives.
The colors?
Black represents the sin that Adam brought into our world.
Red represents the Blood of Christ that was poured out on our sin.
White represents our clean and forgiven state after Jesus's cleansing blood.
