I suspect the surrounding blue can be a factor. Also, it may be the outer edge of the sun would actually appear yellow if isolated from all other light. This is because only the upper atmosphere of the limb (outer edge) is all we can see and it the upper atmosphere of the sun is cooler. Thus, we will receive more greens, yellows, and reds than in we see in the central disk regions. The temperature difference we see at the limb is around 5000K vs. the central region of 6390K.

However, the worlds largest solar telescope (McMath-Pierce at Kitt Peak) reveals the disk to be all white. But, I need to be sure they use no filter. Another possibility is the fact they are over a mile above sea level which reduces the loss of blues due to atmospheric extinctions.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.