Using y4mcolorbars at console as indicated here:
http://linux.die.net/man/1/y4mcolorbars

I was able to produce a color bar NTSC test pattern. With this command:

y4mcolorbars -n 200 -It -S 420jpeg | yuvplay

I still haven't figured out how to store this as a video to use it as a trail-in trail-out on my sequences.

I suggest if could be included as a generator into kdenlive, would be a nice feature!

Best Regards

I have a bunch of Frei0r test pattern generators more or less done, one of them can produce various types of color bars.
Will probably push them this weekend.

great!, I await them eagerly.

Best Regards

Have you already put the color bar generators?

Thank you

Yes, I've pushed the test pattern generators to the Frei0r repository about a week ago.

The one that does color bars is "test_pat_B", types 0...4

After compiling and installing, melt should find it automatically.
(melt -query "producers"
melt frei0r.test_pat_B Type=0)

Is there a way to access this generator from within kdenlive?

I think not, but if there is interest among users, the developers will probably include that option.

Although I don't use color bars as much as I used to, it would be helpful to have it and tone available from the generator dropdown within kdenlive.

You could just look for images on the net and create a sine wav file in Audacity, combine them in Kdenlive, render, and ready for whenever you need it.