html output style fix + error fix if more then 15 conditions without color specification is used

hello,

I just realize, i have bug in detecting light/inverse detection in html output

also I realize while trying to realize what do you mean with one default bg color) that if more then 15condition is used withou colors specification, then array @colorpresets is truncated and perl is complaing:

Use of uninitialized value in concatenation (.) or string at ./colorize.pl line 60.

so also fix for this 

and tuned colors for html output, to be more readable

have also test case if you want to check it

t.