Cool colors at the 'turning edge'?

[Minh Thong]

My very limited painting education has been almost entirely from 'The Students Guide To Painting' by Jack Faragasso, which generally emphasizes nine values of flesh colors for an entire portrait or figure. There are only a couple sections on 'vibrating a fleshtone' by using a cooler mixture, and no demonstrations of the practical application of this.

However, I have read in other texts about using a cool color (Viridian was mentioned specifically) right at the edge of the shadow. But I'm not quite clear on actually DOING this nor what the effect is supposed to be.

In the cropped section of a self-portrait below you can see that my 'turning edge', especially at the nose, is rather blah and doesn't flow into the shadow. Can someone comment on how a cool color would help here, and possibly the best method of application?

Do I lay in a stripe of my home value fleshtone mixed with Viridian and then just blend it into the flesh and shadow? Should the flesh and shadow be repainted at the same time so I can blend wet-into-wet?

Thanks, in advance, for any help at all.

Thich Minh Thong