The Filter module allows for the modification of features in the image by their colour by simply clicking on them. It's as close to a post-capture colour filter wheel as you can get.
Filter can be used to bring out detail of a specific colour (such as faint Ha, Hb, OIII or S2 details), remove artefacts (such as halos, chromatic aberration) or isolate specific features. It functions as an interactive colour filter.
The Filter module is the result of the observation that many interesting features and objects in outer space have distinct colors, owing to their chemical make up and associated emission lines. Thanks to the Color Constancy feature in the Color module, colours still tend to correlate well to the original emission lines and features, despite any wideband RGB filtering and compositing. The Filter module was written to capitalise on this observation and allow for intuitive detail enhancement by simply clicking different parts of the image with a specific colour.
StarTools is famous for its Color Constancy color rendering.
As of StarTools 1.6, you get the choice of two noise reduction styles.
StarTools' Deconvolution module allows for recovering detail in seeing-limited and diffraction-limited datasets.
A luminance mixer allows for re-mixing of the contribution of each color channel to brightness.
You can convert everything you see to a format you find convenient. Give it a try!