I can't get areas with same RGB selected

[jparnold]

I have been using the magic wand successfully to select areas with same/similar RGB color value successfully for a long time but I just can't get it to work with a particular image.
Refer image below where I have used the left mouse button to click in an area on right of the yellow colored area and the magic wand is selecting most of the area to the left even though the 'stripes' are of a different 'shades' even though I have the tolerance set to o (zero). Hopefully you will be able to see the dotted lines around the areas which the magic wand has selected.
What is causing this and what do I need to do to select only those parts of the image matching the same color (yellow) that I select?

[flagpole]

I should try a different Match Mode. Maybe 'Perceptual'. Though im not sure on the calculation it uses.

[Jean-Luc]

Uncheck Anti-alias.

[jparnold]

Thanks 'flagpole' and Jean-Luc
I will have a look at those suggestions HOWEVER -
I thought that I 'answered' this but obviously not.

I found that it seems parts of the image are just too small in pixels to automatically select using the magic wand (see below re anti-alias). I ended up doing a RESIZE larger, doing the magic wand select on the enlarged image which then worked the way I wanted it to, making changes and the doing a RESIZE back to the original size. Maybe unchecking Anti-alias would also answer/prove this method?