Is Pink or Blue Dye Pregnancy Tests Better?

Is Pink or Blue Dye Pregnancy Tests Better?

Which test works best? Which one is more prone to false positive results? Should you buy a pregnancy tests that uses pink dyes or blue dyes? How about ovulation tests?

In this article, we're talking blue dyes vs. pink dyes. Which is better for both OPKs and pregnancy tests?

Pregnancy tests

Pregnancy tests are testing for hCG levels in your body. hCG is a hormone that is generally only produced when you are pregnant and it doesn't begin to be produced until the embryo implants itself into your uterus.

So pregnancy tests are testing for this hormone, whereas OPKs are testing for a completely different hormone. The thing with pregnancy tests, when we are reading a pregnancy test, obviously there's a control line, just like with the ovulation test, there's always going to be a control line and then there is a test line. With pregnancy tests, if there is any sort of faint line on the test line at all, then this indicates that you are pregnant. So if you have any levels of hCG in your body at all, this indicates you are pregnant.

Even the tiny semblance of a second line on your pregnancy test strip is going to give you the impression that you are pregnant, right? Well, this should be true, but there is something called an evaporation line or an evap line.

blue pink Evap Line Pregnancy Test

Evap line on pregnancy test

The evaporation line is a line that shows up on your pregnancy test, along the test strip portion. So it doesn't affect the control line. But just along the second line, the test strip line. It's a line that appears there as your urine evaporates.

This evap line tends to have no color to it. So more of a gray. And this can happen with the pink strip test, but it's a lot more likely to happen with the blue dye test strips.

Is pink dyes or blue dyes better when picking out a pregnancy test?

In general, it's way better to use the pink dyes. So why is the pink dye better? Well, if you go online, look at forums, ask around any women that have been doing a ton of pregnancy tests, they will tell you that the pink tests seem to be better because the blue tests seem to give a lot more false positives. So the blue tests seem to have more evaporation lines. This is due not only to the color. So as I said, the evaporation lines tend to be sort of a gray looking color. So if you're looking at a blue dye test and you see the control line is blue and then you see a grayish sort of evap line, this gray and blue color are sort of similar looking.

But if instead you have a pink dye test, so you have the bright pink control line and then you have sort of a gray evap line on a pink test, it's going to be a lot more noticeable to your eye to see that this second line is gray and not a pink test strip line.

So not only is the blue test just more difficult to read when it comes to the color differences between the blue in the evap line compared to the pink in the evap line.

Pink pregnancy test are more reliable than blue pregnancy test

Not specific studies, but just from anecdotal evidence or just people talking in general. The word on the street is that pink tests are just a lot more reliable than the blue test. Easier to read and more accurate as well. But as I said, there's no actual scientific studies to this. This is just what everybody online and everybody that I have talked to says about these pregnancy tests.

OPK blue test vs. OPK pink tests

So now when it comes to OPK tests (ovulation predictor kit), should we be worried about the blue tests giving us false positives compared to pink tests?

And the short answer is no, you should not be concerned when it comes to the ovulation tests. The reason for this is when it comes to pregnancy tests, any sort of faint line on that test, the test line, having any sort of faint line should indicate that you're pregnant. But when it comes to testing for ovulation, if you see a faint line that is lighter than your control line, this does not indicate an LH surge.

That is basically why you should not be worried when it comes to blue test strips for ovulation. When we were using OPKs test strips for ovulation, what we are looking for an LH surge, a surge in your luteinizing hormone levels. We are looking for the test line to be or darker than the control line.

Because we were looking for it to be very dark, you're not really going to have the problem with the evap line. Because evaporation lines only happen when you're looking for a very, very faint line.

blue pink evap line opk ovulation test

Bottom Line

So in general, when it comes to ovulation test, you don't have to worry about if it's pink or blue. But when it comes to pregnancy tests, if your hCG levels are still very low and you're looking for a very faint line, you're better off getting a pink dye test rather than a blue dye test because the pink ones have less of a chance of having false positive readings.