An A320 Captain reported that TCAS RA displays during bright daylight condition are too dim and interpreting them accurately distracts the flight crew from looking outside for visual confirmation of the threat.

Narrative

[We] received a TCAS RA to adjust vertical speed. Problem; crews with white shirts; morning sun reflecting on MFD displays. TCAS RA information on PFD was so impacted that it was unreadable without focusing on the PFD versus looking out the window at the threat. It occurs to Captain [reporter] that 100% of the RA events he has experienced in daylight condition have had this issue. Our training materials complain that we over respond to the RA and should only respond to the extent necessary. On this event Captain had not engaged the autopilot yet. The TCAS RA always comes as a surprise. ATC had just pointed out the other aircraft and indicated they were stopping 1;000 FT above our assigned altitude. Captain responded by reducing vertical speed; tried to determine if he was in the proper response range (in the green); discovered the TCAS information was so dim compared to the remainder of the PFD that it was unreadable; correctly leveled the flight at the assigned altitude and LOOKED out the window at the conflicting aircraft.