Joel,
When I started building courses years ago, I used PowerPoint for a lot of my media creation. My Photoshop and Illustrator skills are a little better now, but I still use an online tool that I discovered when I was trying to create scalable vector graphics (.svg’s) early on.
Check this out:
https://image.online-convert.com/convert-to-svgThis tool does a pretty good job of turning any image into an .svg. I used it for my submission to this challenge. As long as you have a strong contrast between image and background, (or, better yet, have a transparent .png), you can pull down an image that will import into PowerPoint as a graphic. Once in PowerPoint, you can right click on the .svg and convert it to a shape. This will split the image into many different individual items. Open the selection pane (Home > Arrange > Selection Pane OR Shape Format > Selection Pane). You’ll see a group with several different items. You can then bulk color all the individual items the same color on the slide. Duplicate the slide and then change the color of all the items. Repeat this process for each color in your project. Then, click on each item and ‘save as picture.’
To maintain my sanity, I usually adopt a naming convention like: item_01_blue, item_01_green, etc. Then you’ll have a pixel-perfect version of individual items in each color when you import them into SL. You will probably have to do some freeform hotspot drawing for curved or irregular shapes, but the images that users see will always align perfectly.
Just my two cents. Good luck!