This is Commander. They will seldomly be dead cards. At least not for color. The issue may be that the CMC is 6, 7 & 8. But having 3 of any given color should seldomly be an issue.
On that topic, you have plenty of lands. I would minimize those lands that enter the battlefield tapped. You have everything: cycling lands, scry lands, lifegain lands, along with a few utility lands. You are basically guaranteeing that every land will ETB tapped, thereby slowing you down by a turn. Every turn. Guildgates are just plain bad in EDH. There is no upside. As are the staight-up tap duals like
Foul Orchard. You have plenty of ramp for color fixing. Don't use those. Replace with better lands. Even if you don't have duals that can enter untapped, basic lands are superior to these. As for the others I mentioned, choose one or two categories that seem to help you the most and go with those. I personally like the scry lands and cycling lands for this deck. I would replace the lifegain lands and most of your utility lands. You currently only have about 12 basics in the deck. How often will
Fertile Thicket really hit? Not worth the slow-down. With so much color fixing, will you ever need the sac ability of
Timberland Ruins? Again, not worth the slow-down.
I also don't get the mix of snow and non-snow basics. But that's just my own aesthetics and not really a game play issue.