Rating symbols explained

In numbering the problems on pictures of various boulders, I've tried to find a system that would give a quick visual reference for someone looking for a particular difficulty level.  I first encountered a system like this while bouldering in Las Vegas, where the guidebook I used had the problems marked in circles of different colors, and I could quickly flip through the pages looking for "green" and "blue" problems that would make good warmups.  In trying to adopt a similar system, it occurred to me that I know at least three climbers who are colorblind, and I decided to use different symbols in addition to different colors.  The resulting system is a bit cumbersome, and I'm still not entirely happy with it, but here is how it works for now:

Below is a picture of these symbols in use.  Each of the four problems is indicated by the shape and color appropriate to the rating.  For example, problem #1 is marked with a blue diamond, indicating that it is within the range of V6-V7.  Each problem starts approximately where the bottom end of the line is, rather than at the symbol itself.  You'll also notice dotted lines in some pictures.  Problem #2 in this picture is shown as a dotted line to indicate that it diverges from the main line until rejoining it at the slot.

In the case of the picture below, problem #3 is marked as a dotted line to eliminate confusion about where it goes when it crosses the lines of problems #1 and #2.

Like I said, it's not a perfect system, and I'll happily take suggestions about how to make it more user-friendly.  Any changes to the system will also be reflected on this page.