"I got them but they're white, how do I make them look like in the movie?"
These two questions come up quite a bit here on the GBFans forum so I thought I'd try and clear up some of the confusion.
As some of you may already know, the original pads were customized volleyball kneepads made by Markwort and are no longer available from them in that style. Thankfully there are a few substitutes out there that are very close in style to the original pads. If total accuracy is a factor, then it is important to purchase the large or "adult" size pads for both accurate size and comfort regardless of whether the seller states that "the kids/youth size makes an ideal elbow pad for an adult". Medium/small/youth sizes tend to be very tight on the arm when worn with a uniform and the bubble is smaller than those used in the films. When customizing your pads to match the film, gray dye is most commonly used but many fans have opted to use gray fabric paint instead of dye, the reason being that the elastic/fabric armbands and the foam bubble sometimes do not take dyes very well. Another solution to changing the color of the bubble is using gray spraypaint or primer. Those with airbrushes can concoct a mixture to give an even closer match. Since these pads are meant to be used in physical sports with a lot of movement involved, they have several extra inches of elastic fabric on each end, designed to keep the pad in place during play. This needs to be removed for accuracy's sake. The simplest solution is to roll and tuck the excess fabric under the armband. The most accurate method is to cut the excess material off and either hem the edges or singe them with a lighter and apply some sort of anti-fray solution such as Dritz Fray Check. The small black patch on the inside of the armband is black elastic fabric. It is unknown why the patch is there in the films, possible reasons include covering a hole or brand emblem.
Here are a few shots of the armpads taken from the first Ghostbusters:
There are three different companies at this time that offer accurate pads:
Century Judo Kneepads
Century Judo Kneepads can be purchased either directly from Century Martial Arts, or from KarateDepot.com. Although the item page at Karate Depot shows a clean pad with no logo, it does have the same small latex "Century" logo as shown here. This can be removed with a razor blade (slowly and carefully, don't hack it off) leaving no noticeable scarring after the pads have been painted. The armband on this brand takes gray fabric dye better than the Pro Series 3Pc. pads but perhaps not as well as the Defender pads.
UPDATE: Karatesupply.com has these pads for $15.99+shipping: http://www.karatesupply.com/Judo-Knee-Pads_p_801.html
UK residents can get them here: http://stores.shop.ebay.co.uk/MMA-Fight ... QQ_armrsZ1
Pro Series 3Pc. Volleyball Kneepads
Pro Series 3Pc. kneepads can be purchased from Cannon Sports either directly or through their sale on Amazon.com. These pads, while having an accurate bubble and being comfortable on the arm, have a hole on the inside of the armband and the band does not take gray dye well(see picture below). Fabric paint on the armband and a black patch to cover the hole is the best way to bring this brand of pad to a screen-accurate appearance.
Defender Volleyball Kneepads
Defender Volleyball Kneepads closely resemble the pads used in the film but can be difficult to find. They are currently sold only by an eBay seller known as typj. The most accurate size is large but they have been out of stock in that size for quite some time. They do have large black pads but these have proven difficult to get to a screen accurate appearance. The armband on these pads takes gray dye very well.
Martin Volleyball Kneepads
Martin Volleyball Kneepads can be purchased from KM Sports' eBay store or from Recreation technology LLC. These pads are accurate as far as appearance but the Martin logo has proven very difficult to remove and is very noticeable when painted over.
Here are some examples of the pads I own and have customized:
This picture is to show the size difference between medium/youth and large/adult:
For the rest of yous guys, feel free to post pics of your own pads and a little background on how you painted/dyed them