I've been hearing lately how using a flat iron can cause your hair color to fade quickly. I think this has been happening to me. I sometimes use a heat spray but it just makes my hair feel sort of greasy. I usually don't use it.

Can heat really affect hair color?

Heat causes dryness which makes hair porous which can make color and perms not last as long...Also if you are colored red, for some reason that color won't last as long as other colors.

Also Clare, you should always coat your hair with a silicone sealant before applying a flat iron to it. My hair dresser recommends Aquage Straightening Ultra Gel which contains a blend of silicones and Sea Fennel oil. It works wonders on my hair (when I straighten it)

And one more thing, hair color fades with repeated washings. You might want to use a color intensifying conditioner to help maintain your color between colorings.

I have the Aquage flat iron spray. It makes my hair feel greasy.

This is a gel which you use sparingly. But if you use too much of it, yes it certainly can make your hair feel greasy.

Try different brands. The important thing is you should always seal your hair first.