duck_ as mentioned before by me and by Medico you most likely messed up the image/border/colors for TFFatLineBorderBlueBG in clientscheme.res
Seeing a magenta color like this 99% indicates a missing texture, confirm with 'showschemevisualizer clientscheme' in console and check your borders.
The images for spectatortournament.res can be found in /materials/vgui/class_portraits
- The ones in tf2_texture_dir.vpk are the actual vtf images
- The tf2_mix_dir.vpk vmt files control how the vtf images look ingame