I have 2 guesses: either that phone number is of a guy you really like or some random toll free number with that called you 
Actually, my job is to help obtain funding for the university I go to, so I make lots of calls. I am notorious for making notes about certain numbers
I saw 3116 and I circled it and wrote that I really like that number.
3 for me is blue for me, 1 is white(as is 11) and 6 is dark blue
Edit: As for as I know I'm not synesthetic...
1 white
2 red
3 blue(bit vage)
4 brown(bit vage)
5 yellow
6 darkblue
7 green
8 brown
9 purple(very vage)
10 black(vage)
For me:
3-greenish a little darker than the one in the pic. It is a strong number
4-blue ♥
5-orangish red. Think of a peach on an edge where it is red transitioning to orange. This is a number that is like one of those friends that is nice to you but you know is a jerk. (so I don't like it much)
6-♥ It is a pretty color that is a nice engulfing dark purple and blue and it is a number I really like. It is like the absolute best friend and it reminds me of hugs <(^_^)>
7-It is an orangeish yellow color that I don't like much, but as a number it is okay.
8-A mix of red and blue that kind of merge into one, but are distinctly separate. I can only see one color at a time.
9-I like pink, sometimes, but not this pink
It is a really dull, boring pink
10-brown, but I don't like it
11-This always reminds me of black and white (not gray, but distinct blobs of black and white flowing together). It also reminds me of a rational and irrational mix (like using rational reasoning for irrational things or visa versa). I actually met somebody that I almost instantly associated with 11
13-Eh, it is a shade of red, but it is far away in front of me. It is like looking through a tunnel at it
15-blegh
18-♥ This is a mix of red and black blobs and it is really emotionally driven. I know another person that I associate with this number
19-Ewwwwww. I don't like this number much. It just feels gross
23-I dunno, I just like this one, but it seems crazy (a little imbalanced, mentally)
27-Is more of a yellow color
28-I don't know how to describe this.
34-More brown, but other colors mixed in
42-I have associated this with myself for as long as I can remember. It reminds me of green and purple with a slight mix of blue. Think of a material that is well mixed, but if you look closely you can still see the individual bits.
43-it is kind of a sharp, but pleasing number. The color is more toward a green you would find somewhere in the woods. I know a person that reminds me of this
69-I have been asked about this one a lot. It has always been a really dull, gray, lifeless number. Imagine my surprise when I learned its other meanings
72-It is just a messed up, crazy number. It is a sick yellow color and it is something I don't like to be around. There is a person that reminds me of this, but usually when I don't want to be around with him. Otherwise, he reminds me of 73
73-This is another yellowish color with a slight tint of orange and it can be pleasant for a little while.
86-Kind of like 34
...
Lots of other numbers
I had to go through each of the numbers and figure out what they remind me of, so I picked out the ones that have the most pronounced feelings up to 86
Numbers like 11 or 18 typically change shapes, but otherwise the colors are always there and many numbers make me see colors. Also, in some situations I don't see colors. For example, when I program in hex, B means something else than 11. It only happens when I see the numbers and recognise them as numbers. Also, many numbers I see as individual numbers (like when I see 86 I don't think of 8 and 6. It is just 86).
