2 more at leastYes just needs more coats, in my experience when going over strong colours you'll do another coat or two or three and think that kind looks OK but you'll know you gotta do just one more!
It's Johnstones or Johnsons white emulsion not sure if that's the vest to use on a colour change I found on Google 3 in 1 vase coat not sure it's worth buying to be honestIt does look like the first coat is rather thin. A "strong" colour change is likely to need 2 or 3 coats. Cheaper paints tend to cover less well.