Weird transparency issue with HTML5
So I'm creating an HTML5 site with Animate CC. I've done a bunch of actionscript stuff in the past but this is my first time with html5. I've barely done anything so far but I've noticed two weird issues that I want to address before I get too far along. When I did a test render, the upper layer appears to have a transparency on it that wasn't intentional and doesn't appear in the fla. Even the black linework on the background layer appears to have a white edge around it as well.
Here's a screencap of what I mean:

The white around the black lines is a little hard to see in this screencap but you can clearly see the bush through the outhouse even though there's no transparency there.
It was also kinda slow to render, which is odd considering how little I have done. I even got this error message:
"WARNINGS:
Frame numbers in EaselJS start at 0 instead of 1. For example, this affects gotoAndStop and gotoAndPlay calls. (5)"
At this point I haven't done any coding at all so this warning seems weird.
Can anybody advise me on these issues?
Thanks
