Tomato

This tomato is under near lethal stress. The rolled leaves and prominent veins would seem to indicate that its resources are stretched to the limit. Possible stressors: buying a transplant already in flower and fruit and transplanting, too small a pot, overwatering, cold nights (below 50), Improper fertilization etc. The purpling I am seeing is usually related to lack of Phosporous uptake which can be due to cold soils or wrong pH. If you want to continue to grow this plant, you need to remove all flowers and fruit, use a liquid fertilizer on the leaves and soil (fish emulsion is good), check the pot for good drainage (never just use ordinary soil, it compacts). We presume that the pot has good drainage holes. Tomatoes should never sit in water.