I doubt that there is a real-world market for black opaque-colored silicone tubing; and if there were black silicone, you may not want to use it. The commercial selling points for silicone are that it is transparent, so connections and flow can be readily confirmed; flexible (due to the normal 30%-40% un- and partially-polymerized silicone monomers (silicone oil) content of commercial silicones, which is what makes silicone flexible and tacky); and non-toxic. And how would the tubing be opaquely-colored black? I can't think of any food-grade black dyes, with many or most dyes suspect (e.g., carcinogens); and if carbon black pigment is used, well that has high polyaromatic hydrocarbons (carcinogens) content, with carbon black being soot from partially-combusted organic materials.
To resolve your basic problem, wanting to hide resin build-up, why not wrap your tubing with tape, or at least the section where condensation/build-up occurs? Such as basic black electrical tape, bicycle handle-bar tape, or select from a wide variety, including colors, of silicone tapes, probably available from the same sources as tubing. Or if there is no mouth or flowing air contact, simply spray or otherwise paint your tubing black.
If high temperature exposure is not a concern, consider thermoplastic elastomer (TPE) tubing, which is now replacing silicone tubing for many bioprocessing and other ultra high-purity uses. TPE, unlike silicone, is a thermoplastic, i.e., can be melted and heat-welded to make strong joints; and is cleaner, in the sense of lacking all the non-fully-polymerized gunk of silicone. For example, see
http://tubingandfittings.eldonjames.com/category/flexelene-tubing, which includes colored tubing; and
http://www.advantapure.com/advantaflex.htm. Many others make and sell TPE tubing, and probably cheaper too (food vs. biopharmaceutical grade). C-Flex is another established brand.
