I just started playing with a Philips WEB Cam and indi_v4l2 in an effort to get some nice images of Mars.
I can stream in black and white and use Siril to view the results. However, when trying to stream color the images are messed up.
What am I missing?

Can you stream in color using any other app?

Well, it is probably 10, 11 years ago I did this last time using a Philips ToUcam Pro 740K. If I recall correctly I used a Linux app called qastrocam that allowed me to stream the output to obtain large number of color images that I could process via RegiStax to get high quality images of Mars, Jupiter or Saturn.
The camera also came with a windows program that allowed me to do the capture.

I still have this WEB Cam and it works fine with indi_v4l2_ccd to stream gray-scale images, but I have not been able to get the streaming to work with color images.

I did some research about qastrocam but it is apparently no longer maintained.

I have one of those kickign around somewhere, haven't used it for years. What i do remember, back in the day it was pretty popular for doing astro stuff, but most progams doing that would put the camera into a special mode where it returned the equivalent of raw data without applying bayer color mapping, then any color was added during post processing by the program interpreting the raw data.

If you used one of those programs way back, and it put the camera into that mode, and saved the configuration that way, the issue may well be that the camera itself is now set to return data in that format.

It's been years since I fussed with one of those, dont remember all of the details, but I know that camera was used extensively in that mode back then. I believe (but may be mistaken) the settings involved were persistent in the camera, so wondering if that's what your camera is doing today.

This is why the question is, can any other current applications stream color data from the camera, pick one, any one of the current generation of linux webcam applications.

Few weeks ago I found my old Toucam Pro. I just tried it again after years! It works!

I recorded a ser file and it is in black and white when I open it with Registax.

The Video4Linux driver work for this cam in YUV format. To have some RGB a convertion should be done, I suppose that here the images are stored in the ser file have only the luminance layer (It is the green channel which has the resolution of the sensor). The red and blue channel are 4 time smaller.

Jean-Philippe

Found and did some initial testing of "qv4l2 - A test bench application for video4linux devices".
This program allows the capture of single frames or streams of frames at selectable frame rates (5, 10 or 15 fps) either in black and white or color. The display is done via mplayer as default. Apparently the default format of the stream is MPEG.
The graphical interface allows detailed control of the various camera parameters.