Mix the tomatoes, green and black olives, capers, and green onions in a medium-sized bowl with a lid. Tupperware/Rubbermaid containers work great for this.
Mix the brines and juices together in a measuring cup.
Add the sugar and stir until it’s dissolved.
Pour over the tomato and olive mixture and mix well.
Cover and refrigerate for at least one hour before serving.
When it’s ready, shake the salad in the container with the lid or stir so the brine mixes well.