Tags with special characters (e.g. `+`, `-`) do not apply tag coloring for `tags.<Tag>.color`

I want to color my tags by project and by use-case. For tags without any special characters this works, but once I have tags which contain special characters like `+` or `-` this is not working. I have projects which use the `+` sign and the `-` sign is used for tickets.

Here is the config (when running `timew config`):
```
color = on
confirmation = on
debug = off

define exclusions:
friday = <8:30 12:00-13:00 >17:30
monday = <8:30 12:00-13:00 >17:30
saturday = >0:00
sunday = >0:00
thursday = <8:30 12:00-13:00 >17:30
tuesday = <8:30 12:00-13:00 >17:30
wednesday = <8:30 12:00-13:00 >17:30

journal:
size = -1

define reports:
day:
axis = internal
cell = 15
day = yes
holidays = no
hours = all
lines = 2
month = no
spacing = 1
summary = yes
totals = no
week = no
weekday = yes
month:
cell = 15
day = yes
holidays = yes
hours = all
lines = 1
month = yes
spacing = 1
summary = yes
totals = yes
week = yes
weekday = yes
summary:
annotations = yes
holidays = yes
ids = yes
week:
cell = 15
day = yes
holidays = yes
hours = all
lines = 1
month = no
spacing = 1
summary = yes
totals = yes
week = yes
weekday = yes

define tags:
XL2:
color = color09

define theme:
colors:
debug = blue
exclusion = gray8 on gray4
holiday = gray4
ids = color13
label = gray4
today = rgb521
description = dark.theme: A default, 256-color theme
palette:
color01 = white on red
color02 = white on blue
color03 = black on green
color04 = black on magenta
color05 = black on cyan
color06 = black on yellow
color07 = black on white
color08 = white on bright red
color09 = white on bright blue
color10 = black on bright green
color11 = black on bright magenta
color12 = black on bright cyan
color13 = black on bright yellow

verbose = on
```

And here is my `timewarrior.cfg`:
```
# Theme
import /opt/homebrew/Cellar/timewarrior/1.7.1/share/doc/timew/themes/dark.theme

define exclusions:
monday = <8:30 12:00-13:00 >17:30
tuesday = <8:30 12:00-13:00 >17:30
wednesday = <8:30 12:00-13:00 >17:30
thursday = <8:30 12:00-13:00 >17:30
friday = <8:30 12:00-13:00 >17:30
saturday = >0:00
sunday = >0:00

reports.summary.ids = yes
reports.summary.annotations = yes
tags.XL2.color = color09
tags.SP+OC.color = color01
```

Is there any way to escape these kind of symbols or is it simply not working currently?