Hi, I just filled my Kuretake Sumi (the red one) with noodler's black ink, the first time I use this brush pen. It's a new bottle of noodler's that has been sitting for many months. The result is the ink is a light grey. Not dark at all.

So I shook up the noodler's and then refilled it and now the ink is like a medium grey but still not black. Shouldn't it be black? I squirted some of the ink on my paper from the syringe and it's definitely black ink.

I'm not sure what to do.