I always thought that the link colour has to be different from text colour?

I have come across a site http://www.printandpackaging.co.uk/ and it has made me question this belief, they seem to only have bolded the link which would be very nice if this is  fine.

Sorry still a little confused,

So why do links need to be in relevant content if links from charity websites unrelated to the industry in no content pass value?

Yes I know I need to get rid of the bad links but how if I have contacted the site owners, we are not under any penalty that I can see other than the fact that the links maybe toxic and hurting our site a little U do worry if I use the Google tool we may be causing more trouble?

I am currently building links to our website via estalished blogs ect (2+ years old), As far as I understand even if they are unrelated to what we do (print) as long as the post is about print the link should offer some value is this correct?

Other questions I have which I would greatly appreciate advice in are as follows........

(1) Do charity websites or company websites with link pages ( about5-10 other links) or links / logo's on the front page offer value even on unrelated sites?

(2) What happens if 80% of the link building I am doing comes from blogs?

(3) If I have links that are clearly spam that have been built to our site can they be damaging our potential to rank and how can I remove them as I have tried to contact the relevant parties but fear pressing the button on the google tool may harm our site should I?

(4) If I have a page that genuinely has a lot of mentions of a keyword (not so much the money keyword but part such as wanting to rank for pool table but end up with the different versions of keywords having table mentioned 5 - 10% of the time).

Thank you for your time.