It's been suggested that the lambskin/white leather apron was originally a plain garment worn that was only displayed among Masons and never decorated. The decoration of aprons came about only after the introduction of speculative Masons, many of them noble and/or having money, who wanted something a little prettier than the plain white apron. Hence, the fact that most Masons have gone back to wearing simple, white aprons is really a case of "forward to the past". Whether or not you think that's a good thing is really a matter of taste.
In most places I've been, officers and Past Masters have distinctive aprons which can be worn in lieu, marking their special status among members of the Craft, and this continues when dealing with Grand Lodge officers and Past Grand Masters, whose apron designs become even more elaborate.
Having said all of that, there is a Brother in my Lodge (our Junior Past Master) who has foregone this special display of status, even while serving as Master, wearing a plain white apron despite his official authority to wear a PM's apron. This has caused some grumbling from certain quarters, but it has been my position that it is his right to wear an officers/PM's apron, but also his right to wear what he will, so far as it conforms to the regular usages of the Craft, which merely requires that a Mason be clothed as such, which he is.
TU