I can't find an example of MGIV with selenium to look at right now, but selenium often has a slight warming effect, even though the tone doesn't change much. Try a print or two that way in any case. If you go with gold, Kodak GP-1 (gold protective solution) is a bit cheaper to mix up than the regular gold toners. I know it cools MGIV a bit, and it may be enough. My examples don't show any blue in the shadows, but the shadows are a very neutral, cold black. The developer can have a decided effect when you want subtle tone changes. You might look to a cold tone contact paper developer or one of the other developers expressly designed for cold tones (e.g. Ansco 103, Ansco 113, Defender 54-D, the Burki and Jenny cold tone formula, D-73, Muir's blue black paper developer, or any of a number of others).