Just realize these kinds of filter are not optical quality, in other words, not intended for image-forming applications, but for use in a filter drawer above the negative in an enlarger. I don't know if
this matters in your case, if you aren't after a sharp image to begin with - so you can obviously
experiment with them. But if you want sharper results you would need to go with either Wratten
gel filters or conventional glass camera filters. You can lower contrast by using a deep green filter,
like a #58 or 61, since the low-contast layer to VC paper is green sensitive.