It will actually look more like this (first pick is the old tude)
http://www.followsteph.com/wp-conten.../caulking2.jpg
And I just checked it out you can get black if you want but I am not sure about that one. I have never used or researched it. Seems like if it is 100% silcone and exactly the same product but black it should be ok. Anyway good luck on the sump I have to build another one comin up here and that is what I am using
GE silcone II 100% -clear.
black pic
http://www.homedepot.ca/wcsstore/Hom...aca4eaf1_4.jpg