The pull request that fixes this issue has been merged into the project repo master branch at this commit.

Thanks I think that's a great idea. I'll do some testing with the UIO contrast theme colours.

 I was testing with Safari. The screenshots you posted gave me an idea. We could implement a similar behaviour across browsers by setting the colour of the placeholder and then specifying a lower opacity. Here is a jsFiddle with a quick example. https://jsfiddle.net/j15gyedp/ You can adjust the colour and opacity values to experiment.

thanks and sorry I missed that screen shot attachment the first time. Firefox seems to be doing something different than what you're seeing, I've attached a few screenshots. What browser are you using?

 I guess the basic issue is that we do not style the placeholder text at all at the moment. So it always shows up in the browser default styling. I'm not exactly sure how to best handle it for the binary contrast themes like black-on-yellow, where we only use two colours. It would be hard to distinguish the placeholder text from the other text on the page. In the case of black-on-brown, that is a theme that using several colours so adjusting the colour to something that has better contrast but doesn't look like the rest of the text on screen might be fine.