What is the name of the grape whose wine products had the highest average price?
select t1.grape from grapes as t1 join wine as t2 on t1.grape = t2.grape group by t2.grape order by avg ( price ) desc limit 1
What is the color of that grape?
select t1.color from grapes as t1 join wine as t2 on t1.grape = t2.grape group by t2.grape order by avg ( price ) desc limit 1
What is the color of the grape whose wine products had the lowest average price?
select t1.color from grapes as t1 join wine as t2 on t1.grape = t2.grape group by t2.grape order by avg ( price ) limit 1