Changing component colours using colour by tag

I have built a tiled roof and created a mess I can’t fix.
I imported a single tile from the warehouse, made a large array then saved parts, which I then trimmed using solid tools and made components of each of the saved parts. I have done something different as shown on the components Capri Area C and Capri Area D as shown in the sample.
I didn’t bother with fixing these as I intended to finish with a single component which I thought I could colour with the default and “colour by tag”.
That works for me but the colour by tag changes the colour of every tag.
I have spent a day trying to fix this to no avail.
Sample.skp (4.2 MB)

You don’t mention clearly enough what exactly you are trying to achieve here. Are you simply trying make all the tiles the same color? I’m guessing. Using sold tools to build this model makes many off the components unique which makes it much harder to make changes. Color-by-tag will default apply a different color to every tag so that they can be quickly distinguished from each other, but the color applied to each tag is user editable so you could set multiple tags to have the same color. But are you planning on only viewing your entire model in color by tag? That sounds limiting and cumbersome.

If you just want to make the the existing tiles the same color without painting every one try removing the existing colors from your model, and replacing with the default, then you can color all with a click.

I’m not sure this level of detail is really required for a tile roof but if it was I might consider using section planes to slice the arrays of roof tiles instead of actually cutting them.

I am trying to make a tiled roof all with the same texture and colour. I’m a beginner and am making a model of my Auntie’s new house and I used solid tools as a learning exercise; I already know how to use the section cuts. It took me about twice as long to do the same thing with solid tools and I won’t do it again, but I learned a lot.
My mistake was to assume that colour by tag was colour by each separate tag which is not the case.
I can’t understand what I did to generate two different sets of components even though I thought I was doing the same process for all the components, maybe something to do with faces or unknowingly making them unique?? A bit of exploding has fixed that!
Notwithstanding, I will do as you say and thanks.