Took yesterday off to take the wife to the beach. Had a great time and only burned a little. Those spray on suntan lotion works well as long as a gust of wind doesn't pop up as you spray

Look like a "painted" pony!
Looks good so far Fuji. 
Here's a shortcut to finding a good faded shade of white: Copy the white layer and paste it to a new layer just above the white, invert the white to black and now just use the opacity slider to adjust the faded look. On my skins, white markings are faded with about 10% black - and black markings faded with 10% white. by having a separate layer for the shading, you can adjust the color on the fly when making adjustments until you find the percentage that you like best. My advice is no less than 5% and no more than 15%.
Ill check this out too. Im usually pretty good at coming up with easy ways to do things, but I just don't know Photoshop that well yet.
Also, regardless of how you weather it, remember that the white paint wouldn't be PURE white.
Simmers Paint Shop AFAIK doesn't have any color swatches for WWI, but you might take a look at the German swatches for some examples. Wasserhell (250, 247, 241) might be a good choice to start with.
Took a look at that and the white I used is darker than that one already. I used 224,215,202 as my base. I wanted to be sure I left some room to use a brighter white for some highlights.