"Positive ripples" refers to the idea that doing something good or positive can have a cascading effect, spreading positivity to others and creating a chain reaction of good actions or feelings. Full definition
She'll coach you to throw the pebble that will create positive ripples throughout your life. (includingcake.com)
The continuity of African imagery has brought about a newfound freedom and form of expression for the continent that has caused positive ripples throughout the various spheres of contemporary African Art. (artafricamagazine.org)