For the average joe, the color/s of goal gear really doesnt make a difference but when your playing in situations where its top-tier its a different story. Take a net scrum as one example.
Most times the puck would be released from a reasonable distance from outside and to the sides of the goalies priviledge zone. Given the goal has to contend with traffic at his front and an opponent parked for a redirect, black can hide the puck from the shooter for a fraction of a second, if a shallow rebound is given up. If the puck is not in contrast to the pad it takes just a bit more time to find, if in close to the goalie. Black and dark colors or brilliant colors stand out when thier background is in sharp contrast. Seeing the openings between the goals red outline and the goalie is significantly easier. On hte flip side to this, black and darker blues will also hide a puck from the goalie who has given up that shallow rebound. I personally want to be able to pick that up as rapidly as possible to make a cover. My view as a goalie is more restricted than that of the player in front of me.
To varify it is very simple to do. If you have a white painted wall in your home, have someone tape a pic of a goalie/or other object in dark or brilliant color to it. Make the object abour 5-6" tall. Turn your back so that you can not see where its placed. Time yourself...turn, find and touch the object. Repeat with an object thats color is NOT such as a light grey and finally with a white version. Your time will increase as you progress to the white. Not many want pastel colors plus the difference is much less significant until you really match the back ground.
Some pad designs will also help a shooter gain a more rapid lock on a five hole. Simmons and a few others have in recent years put out graphics that actually POINT to the five hole when the goalie is in stance. Designs with lined graphics may look very cool but with just a short glace a sniper can lock on and shoot with confidence much more quickly.
That .1 to .3 seconds, depending, quicker pick up of the puck by myself can be the difference between a goal or a cover. That same time frame taken by a shooter to lock on target can be the difference between a shot released or my team mate preventing a shot on net or me being in position for the shot ready to make the save.
Over all, black, dark or brilliant colored goal gear only advantages the shooter. White as a predominate and with out graphic design to highlight the pads provide more aid to the goal than the shooter in most instance.
By the way....white or black tape on a shooters blade does make a difference from the goalies perspective. White or color tape allows me to see the shot release much easier. Black tape makes picking that up and my reaction to that shot a tad slower. Given it takes less than .3 seconds for a 75 MPH shot from the blue line to cross the goal line, a shooter who uses white or colored tape is giving the goalie just that little bit more time. Go ahead and keep thinking it doesnt make a difference, USE WHITE TAPE...I prefer that you make my job easier. lol