Contrary to vector layers, colours used in bitmap layers are not linked to their swatch in your scene's palette. Therefore, if you update a colour in your palette, this new colour will be updated in the drawings in your vector layers, but your bitmap layers will remain intact. Hence, it is important to know exactly the colours you wish to use before your start painting on a bitmap layer.
Because bitmap layers are not linked to your colour palettes, this adds extra flexibility when painting on a bitmap layer. Although you are still able to use the colour swatches from your colour palette, you can also pick any other colour and paint right away with it, without having to create a colour swatch for it in your palette. Hence, when a bitmap layer is selected, the Colour view lists your palettes and their swatches, but it also features an extra panel, Bitmap Colour, which allows you to create a colour on the go.
NOTE The Bitmap Colour panel only allows you to create solid or semi-transparent colours. If you wish to use a gradient or bitmap texture in a bitmap drawing, you must still create a colour swatch for it in one of your scene's palettes.
By default, the bitmap colour sliders allow you to pick a colour by choosing its Hue, Saturation and Value. These sliders are referred to as the HSV Sliders. If you prefer, you can also pick your bitmap colour by choosing its Red, Green and Blue values, by switching to the RGB sliders .