Thanks Rob. I checked the colour settings in InDesign and it is retaining the ones I set in Bridge. The colour panel for my swatches is appearing as a CMYK defined swatch, as you demonstrated, cheers.
It seems to be that if I create a swatch, the colour stays stable. However, if I spec the colour via the fill box, it shifts. I've made a little video to demonstrate. As you can see, the colour picker is in RGB when I create the object, then in HSB once I've copied it and return to look at the specs.
Please ignore the faffing around at the end — I didn't know how to stop the recording!
In your .mov capture you tabbed out of the CMYK fields and your cursor was in the H field when you chose the color, so your color choice was HSB not CMYK. If you don’t tab out of the CMYK fields and click OK or Add CMYK Swatch the color will be CMYK.
From your .mov:

Before you selected the H field you could have chosen the CMYK color
