I have a file Avatar.jpg I have used with many other BOINC-based forums, it's 100x100 pixels and 3.9KB so is within the restrictions. However it won't upload here; when I Update nothing happens.

I tried resizing it and then it displayed washed-out yellow (it looks fine at my end) so hoping I can use it as-is. Unfortunately the smallest I could get it as PNG was 18KB. Thanks for any assistance.

No real clue, but try using a different JPG-writing software. There are some JPEG variants (e.g. CMYK ones) which are hit and miss (mostly miss).

Same problem here with washed out colors. Still trying to find different software to manipulate the base image.

Same problem here with washed out colors. Still trying to find different software to manipulate the base image.

I'm using KolourPaint over Linux. It's simple, free, and efficient.

Thanks for the tip, however after an hour of trying every permutation of color depth, scale, size, compression and file type, I can't get anything to upload or produce anything but a washed out image.

Giving up.

I'm using KolourPaint over Linux. It's simple, free, and efficient.

Thanks... that did the trick (well, almost.) I could not get JPEG to work as was always washed out, but it at least had export options for PNG to allow 8-bit colour depth which got the size into the acceptable range. It's badly posterized, but I'll live with it.

Thanks... that did the trick (well, almost.) I could not get JPEG to work as was always washed out, but it at least had export options for PNG...

The 100x100 pixels image final result is due to some server algorithm adapting it to an enough-reduced size.
You can see avatar image characteristics by right clicking over it, then "Show image information"
Doing this over my Avatar, it shows something like this.
I had to play with image quality parameter offered at the moment of saving .jpg file for size being reduced enough (5,02 KB) for server's resizing algorithm not to come in action.
Clicking over your Avatar, it is sized 4,05 KB and .jpg format. Therefore, if you uploaded it in .png format, it has been clearly post treated...

Clicking over your Avatar, it is sized 4,05 KB and .jpg format. Therefore, if you uploaded it in .png format, it has been clearly post treated...

Definitely... the forum has to be converting it somehow as if it were just a save-and-retrieve I doubt this weirdness with the washed-out colours could occur.

I tried both jpg and png formats and 8 bit colors and it either would not upload and populate or it washes out.

Only Zoltan knows...

Only Zoltan knows...

I'm pretty sure that 10 years ago I used ACDSee to crop, resize and save a small JPG for my avatar.
I stripped all EXIF and other metadata to make it even smaller.