I was in same situation as you were but I went with blood red it looks great with clear tubing  https://www.newegg.com/Product/Product.aspx?Item=9SIA9AB53P6499
 

Is this true? Dyes aren't as dangerous as they once were? I have a clear block but was still going to run distilled. Dyes used to clock blocks, cause buildups and other nasty things. Have they improved? Is it still ideal to run distilled? Sorry fi this is considered a thread hijack.

I've never seen advertised loop dyes that last years, especially UV reactive ones. Doesn't mean they don't exist, just that I've never seen one yet. 
 
The longest lasting dye I've ever found was actually made for ponds. It was designed for sustained UV sunlight exposure while remaining safe for fish, so I gave it a try and can say it will last past four years without any signs of it breaking down in 24/7 loops. You can get it in any color as long as it is blue.  8oz is enough to color 4,000 gallons though, so any shade of blue works.  Stuff worked so well I tried some pool dyes, but those didn't even last months. You'll get tired of the loop color long before that pond blue stuff goes bad.

TECH_DaveBKougar, can you give a link to the stuff you tried?

 
Label has changed but I'm reasonably sure it was TotalPond Pond Blue It's designed to be blue without blocking sight of pond fish, but the stuff is so concentrated it's unbelievable. It does not stain tubing or fabrics, but it's so concentrated that it will take considerable time to wash it out of carpet if you spill a drop from the bottle, trust me on that.  Smartpond sells their own "blue tint" version as well, but I've not used it.
 
The second thing I use (and still use) is Algaecide. The key is it must use Didecyl dimethylammonium chloride as its ingredient which most (but not all) Algaecides do. This stuff will prevent algae, bacteria, fungus, and practically anything microbial from growing in a loop, and since it is also designed for fish ponds the stuff will not interact with pond blue coloring. I don't even remember what brand I originally used, but this is the current Algaecide I've added to my loop. It is just as highly concentrated so it doesn't take much to keep a loop clean for two years without adding more. It is much much better for watercooling loops than dissolving silver into the water in my opinion.
 
Both are these are highly concentrated so over the long run it's really cheap to use both over expensive watercooling brands, and both can be found at the local mega-brand hardware stores. Unfortunately I've only ever seen Pond dye in blue, so that's the tradeoff.  Neither have negatively affected my MCP655 pump which has been running in my various desktops for ten years now. Bought that pump alongside a Q6600. 

GTXJackBauer
 
I personally feel that dyes or colored fluids should be used for show rigs only.  For 24/7 use, clear fluids with color tubing and RGBs for color.

 
+1
 
Dyes do not help cool the system ---> would not add them to a daily driver