CMYK confusion (it just doesn't look right...)

Essentially this is what I am doing.. I am opening an existing CMYK TIFF, adding a rectangle filled with a CMYK colour (which I sampled earlier in photoshop from the same file i just opened in code) and saving it out as a new file... It just doesn't work (ignore the lines on the left side): Click here to download image

bitmap = new Aurigma.GraphicsMill.Bitmap(System.IO.Path.Combine(new string[] { basePath, "assets", "blah.tif" }));

Directory.CreateDirectory("output");

using (var graphics = bitmap.GetAdvancedGraphics())
{
    graphics.FillRectangle(new SolidBrush(new CmykColor(12, 95, 84, 2)), new System.Drawing.Rectangle(bitmap.Width / 2, 0, bitmap.Width, bitmap.Height));
    bitmap.Save(@"output\out.tiff", new Aurigma.GraphicsMill.Codecs.TiffSettings { Compression = Aurigma.GraphicsMill.Codecs.CompressionType.None });
}                  

I am sure this is easy for someone that knows Photoshop + CMYK... but for a lowly dev like myself this is greek...

If more info or sample files are needed, please let me know... Any help would be greatly appreciated...

Edited by moderator Tuesday, March 22, 2016 3:31:43 AM(UTC)  | Reason: added text

I was directly putting the CMYK PERCENTAGE values from the Photoshop colour picker instead of translating those to a bit. After the conversion, everything seems to work:

so after some math...

... this

... becomes

This spawns a decent question though, is there a built in way to handle this conversion?