Recently, I added a logo on my website and used it for a while without any problem under IE7 or Firefox. Both of them are what I've used for now. However, yesterday, I worked on an old machine that has IE6 installed. I tried to go to my website and found that the logo which is PNG file didn't work well in IE6. The transparent area went grey in IE6 So, I've looked for the method to solve the problem.
Many of them are as below :
1. Microsoft Knowledgebase
2. Dave Massy's Blog
3. Laurence's Blog
4. fiLi's tech
I looked at all of them and found that the easiest method is to go with fiLi's tech. According to that page, it said that IE6 support PNG8 but not PNG24. So, just convert it using the program in the post (pngquant.exe) and upload a new logo file into the server and that's it. No need to dig into the code or anything else. One thing I can notice is that the logo display is the same as before under IE7, Firefox. But the logo shows under IE6 is a bit blur with very minor color mixed up in the logo. For me, that's fine as long as I can avoid working on the code.