I am not an expert at this, but the last article read about meta tags said that they are now even useless. So I seriously doubt that using header tags have any effect on a search engine ranking at all. After all, they're HTML tags, nothing else. aren't they? robots don't search for HTML tags on pages, as far as I know.
Dont confuse heading tags with meta tags that are placed inside the head section of your page.
As Abdura pointed out, heading tags DO have a great bearing on SEO. If you do a google search on the top SEO tricks, you will find some good articles and gain some knowledge on your own.
I too have a company I work for that is a 100% online based company. I havent looked at the numbers, but I would say that probably at least 75% of our revenue is generated by search engines. Search any product and our site will most always rank in the top 3 if not number 1. And btw, our site rankings are all organic. No pay per click.
Now styling your <h1> tags will have no bearing on rankings, to answer the OP. Search engine spiders look at content, not how the content is styled.