Ian, no worries. Just control as many settings as you can. You Jace to remember that when you take pics in auto mode the camera does what it thinks is correct. If, for example, you have a fairly dark subject as you do here, the camera will automatically overexpose it, making it too light.
In order to calibrate your monitor you need to buy special soft/hardware. I mentioned it only in case you or anyone else was really serious about getting the color correct.
Anyway, your bloom is gorgeous. Must have been something else to see with your own eyes