I love eyedropper tools. They're great for picking up colors from everywhere.
When I'm using Sims' favorite colors for decorating, I try to pick different shades within the color scope, rather than use the exact hex. For example, in mine and my partner's self-sim family, there are three sims that like lilac and two that like orange. Of the three sims that like lilac, one uses a palette quite close to the game's original hex, one uses a very muted mauve that's very close to white, and one uses something in between lilac and purple. Of the two sims that like orange, one uses orange very close to the game color, and one uses a bright yellowy orange that I combine with black. I also try to combine the favorite colors of my couples in their rooms in all my games. In one game I have a bedroom that mixes red, blue and purple decor to fit with the favorites of the sims that use it (the red is the accent). I used to play a web breeding game that was a lot about the art of hex code combining, and I learned how to make colors look good together there. Some colors naturally lend themselves to each other (red and green, blue and orange, yellow and purple) and getting the others to fit is hard, but can be done. If you want to combine two colors that usually don't look good together, changing the shades of the colors will often do the trick. I'll post some examples later that I hope will help builders and decorators, but I'm getting a little burned out, so it will have to wait for today.