Yellow (Gold) - Man was created without any fault or defect to have a relationship with God, to worship Him and enjoy His blessings forever.
Black (Dark) - But man chose to do things his own way and disobeyed God resulting in sin entering his life and him becoming separated from God to live--his heart became spiritually darkened and his judgment death. Everything changed. What was declared very good by God, now was marred by death, disease, and destruction.
Red - Man could not fix the problem he created. God knew this long before the problem happened, and He had an answer. His answer was to send His Son to be born as a man to go to a cross as a sinless, complete, and perfect sacrifice for man's sins. What man could not do, God did by shedding the blood of His Son which covered all of our sins. Not only that, but God's Son (Jesus) did not remain in the grave, but rose on the third day declaring not only His power over sin and death, but also His power to forgive sin and give life to man.
White - God then said that the way to receive this forgiveness and new life was to simply believe that Jesus died for our sins, was buried, and rose again, and then ask in faith for that salvation for ourselves. God
promised that we would be saved and that as a result of that salvation all of our sins would be washed away--forgiven--and that the righteousness of Christ would be put upon us, us who on our own there was no righteousness to be found.
Green - Having received God's gift of salvation we are to then grow in Christ, trusting God to complete the work in us that He began with our salvation. This work continues until we step out of these bodies by death or His coming to take His church and we then fully inherit the perfect for which He created us.
This cycle of life for the believer again points to the purity of relationship (symbolized here gold) which man was created for in the first place.
Apart from Christ man is left in darkness and his sentence is separation from God and eternal judgment.
There are so many Bible verses that come to mind in order to share these truths, but there is one that I really want to leave with, “For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.” (John 3:16, NKJV)