Figure 2. This next one is our local college, Georgetown, which obviously doesn't care too much about football, at least on this field.  I'd still like to avoid the end zone logos, but these are at least not on a fully painted background.  The lacrosse and soccer lines are equal to (or stronger than) the football lines. And they don't put the yard numbers on it.

Over the past several years traveling across the USA visiting different sports facilities I’ve run across several different line marking schemes for multi-use fields.

In a Minnesota school district hosting football, soccer, and lacrosse they followed a white (football), soccer (yellow), lacrosse (blue) color scheme. The white and yellow lines were sewn in while the blue lines were painted. It was a very “busy” looking field with football sideline numbers in the field of play but no end zone nor midfield stencils.
https://picasaweb.google.com/105832309948818480130/LacrosseFieldOverPainted

Another Minnesota school district over painted soccer yellow lines on a football field with sewn in white lines. They did not expand the soccer field outside the football field field which made painting some of the yellow lines next to the white lines. We happen to be over painting existing yellow lines without removing the existing painted yellow lines first creating a thicker (build-up) line. The previous paint used was an oil/epoxy
type of material which felt like a gummy substance, not formulated for synthetic turf application. They wanted a brighter line without “cleaning off” the existing material (saving money).
https://picasaweb.google.com/105832309948818480130/WayzataHSMinn

Our local community supports a multi-use field for three high school football teams and two high school soccer teams. The field uses white (football with numbers and midfield stencil all sewn in, fit within the soccer circle) and black (soccer sewn in line). At first I wasn’t sure I liked the use of the black line for soccer but sports participants said they didn’t have any problem with this color selection. Nemaha Landscape Construction Inc., Lincoln, NE, [http://nemaha.net/] was responsible for this construction and has a lot of
experience specifying and installing sports fields in the Midwest. They may be able to
provide you additional information.

Most fields use yellow for soccer on a football field. I’ve seen red used primarily for lacrosse and blue for field hockey when on a football field (white lines). More state education associations are specifying sideline number stencils on the field of play versus the out of bounds yardage signs/markers. Please check with your state high school activities organization/association. Most soccer fields on football fields will use the back line of the football end zone as the soccer end line and may not have a separate color. I do like your white lacrosse lines on the white football field picture. I wonder what the participants think of this when on the field of play?

I’ve heard that some student have problems with certain colors due to color blindness.

On the paint/chalk marking solutions there are a couple options you can consider.

1)    Permanent field marking paint, bulk latex, can be removed with a cleaning agent, that will hold up for a year, possibly longer, applied with an airless line striper (Tru Mark Trailblazer Solar Trail and Solar Wash).
2)    Temporary field marking paint, bulk latex, can be removed with a cleaning agent, that will hold tournament or season, possibly longer, applied with an airless line striper (Tru Mark Trailblazer Rally Day and Season Ticket and Trail Wash).
3)    Temporary field marking aerosol chalk, applied like a inverted aerosol paint but performs like a traditional powdered chalk (baseball/softball fields), no cleaning agent required, water brushing/foot traffic removes the line. (DuraStripe Aerosol Chalk)
4)    Temporary field marking bulk liquid chalk, applied with an airless line striper but performs like a traditional powdered chalk, no cleaning agent required, water brushing/foot traffic removes the line. (Tru Mark SwitchBack Double Play)
https://picasaweb.google.com/105832309948818480130/DoublePlayLiquidChalkTrials

If you are only playing weekend tournaments for a particular sports activity then the temporary marking chalk solution may be the preferred marking option. There are more facility managers restricting the use of paint on their multi-purpose fields. They do not want to be spending time and resources cleaning the turf to remove lines.

Here's a recent article that you might be interested in. There is a section that talks about field striping and marking. This particular article appears to avoid football as the soccer lines (picture at top of page) are in white, lacrosse in yellow, and two other sports in blue/black and red.
http://www.northstarpubs.com/articles/prb/partnering-to-meet-common-goals

"Striping And Marking

The benefits from fields like these are dependent upon the ability to host several sports. The artificial fields must be lined and marked for multiple men’s and women’s sports, which adds to the complexity and cost of the project. This also requires cutting, gluing, and splicing the artificial turf, which can result in a greater need for seam repair in the future. The basic outline of the soccer fields is incorporated into the turf at the factory, and once the artificial grass is in place, the additional lines are cut, glued, and sewn in. While this slows down the process of installation, it does allow for a variety of tournaments, which adds a positive economic impact."