Not on my computer so can't look at anything right now - just wanted to tell you: look at HugeLunatic's off-grid rugs mod here. It tells you what to do to fix the dark recolors problem (or there's a link to it somewhere in the posy). The answer is in the TXMT.
P.S. For anyone who might be a bit confused now, this wasn't just some out of the blue random post. OP posted a rug conversion on their tumblr and was wondering about the difference in the textures when comparing outdoors to indoors. Thought I'd just post here about it for them.
@mustluvcatz - Thank you so much for explaining the problem. I used the tutorial at HugeLunatic.com (great, very easy to follow) and fixed them up. I made a post just now on my tumblr and the new ones are available there now. Good looking out! I'm so happy you visited my tumblr. I'm putting pictures of my neighborhood Black Gull Bay and it's subhoods there, too. And some little presents for stopping by as well. I'm hoping I can share some of my things here at MTS -- hopefully -- my bigger projects.