And today I learned that you CAN change the colour of the gradient in illustrator.
I was rather frustrated the other day when I couldn't work out how to alter the gradient to put in colour instead of black and white. I just assumed that it must be one of those annoying settings that is locked to being the preset colours. But then I had a brainwave and decided to Google it. I found loads of helpful pages explaining quite simply how to change it.
By clicking on the gradient tool, a gradient slider scale pops up over the top of your object. Yoou then just need to double click on the little arrow toggle at the base of the slider scale and you can set THREE different colours of varying opacity.
Rather cool really.