I recently made a comment on a thread about CAW textures, which brought up a thought.
As some of you may know, I tent to work with CAW, and I have found a VERY useful "mod" to add road textures: Road Textures by Elmigo https://modthesims.info/t/printthread.php?t=495278
I have noticed an issue though.
The dafault road lines have two yellow solid lines in the middle, and two solid white lines on the sides. When zooming out to put it in low LOD, the white lines begin to turn yellow...?
Also, with Elmigo's road line textures, the yellow lines begin to turn white...?
Here is a screenshot of it:

Anyone got any ideas as to why these files are like this, and how to fix it?

The default road detail textures, streetTile_stripes.dds, did this to me as well. It turned out to be a simple fix. The invisible parts of the dds were all coloured yellow. That means that when the mipmaps for the dds are generated, it is blending yellow into the white lines because that's the colour of the invisible pixels around them. All you need to do is open it up and recolour 1/3 of the alpha 0 pixels on either end of the image white.

Or just download the attached fixed road stripes dds

Thank you for the reply.
So, if the default lines have yellow in the alpha, does that mean that these modded textures have white around the yellow lines?
How do I actually edit them? I use Paint.net to edit my dds files. There is a "alpha" section of the color tab, but it is only a white-black thing.

Ya, it's almost a definite that if it's changing to white, then those lines were done over a white background that was then set to transparent or some-such. Unfortunately, I know next to nothing about paint.net so i can't give you explicate instructions on how to correct the files using that program. Hopefully paint doesn't fall too far outside the standard graphics editing setup and you can figure out how to edit them in paint.net if I tell you how I did it in GIMP.

So, how I changed the color of the transparent pixels:

1. Open the .dds but don't bother loading any mipmaps. You should now have an image open with a single layer showing the lines or what ever the .dds has.
2. Create a new layer and move it under the main image layer.
3. Working on the new blank layer you made and moved to the bottom, color all areas the color the invisible pixels in that area should be. If editing streetTile_stripes.dds to make all lines blur out with proper color, your image should look something like this when you're done with this step.
   
4. Select the top original layer and create a mask from its alpha channel.
5. Select the mask for editing and select all then copy to copy the entire mask.
6. Merge the two layers into one.
7. Add a mask to the newly merged layer.
8. Select the mask for editing and select all then paste in place and anchor the newly pasted content if necessary.
9. Apply the layer mask. You should now have a single layered image that looks exactly like it did when you started this. The only difference is the transparent pixels are now what ever color you painted on that bottom layer.
10. Export the image as a BC3/DTX5 dds with mipmaps and you're done.

Thank you. Paint.net has the same system with layers, so I should be aboe to figure it out. Worst case, you used Gimo, which is also free, so I can simply download it and do it there! I only said Paint.net as I was worried someone would come about with Photoshop instructions (which tend to be a good bit different than any free program). I will give it a shot as soon as I get done with my roads!
By the way, say I edit this file, but override the original with the fixed, using the same name, will all roads in the map that use that texture automatically update, or do I need to go and replace each one?

They should but like anything in CAW and the sims in general, what should happen and what dose happen are not necessarily the same thing.

If your textures don't update, going into edit road, choosing a different texture, leaving edit road, then going back and reselecting the old updated one should do the trick. You also might need to do something to the terrain or roads (put down a bit of terrain paint then remove it, move a road then move it back, etc) in the chunks that the updated road runs through to make sure CAW updates it's low LOD chunk textures if the roads still look like they are using old textures when you zoom out.

I know it's been 3 months, but I tried this out finally (I was away from the SIms starting not long after I made this thread) and I still have this issue. I think Gimp changed a good bit from the version you have before I tried this, or something, but I had to resort to Google to figure most of it out (or maybe I just suck at Gimp, to be honest!)

Here is what I did: I opened a file called "no-sides_continuous"; a custom texture from that linked pack in my original post. It has a single yellow line down the center. No side lines. As usual, when zooming out, it turned white. I opened the file via Gimp, made a new layer (named "Layer" by default), moved it below the main layer "no-side_continuous.png" (the name and type of the file itself). I selected the entire center area of "Layer" (behind the yellow line) and used color picker on the line itself, then filled my selection to that color. I then deselected, then filled the rest with white (I plan to use the same image layer for the rest of the files with yellow center lines and white outer lines). I then clicked on the top layer, chose "Add layer mask..." chose "Layer's alpha channel", then clicked the mask, then "select" and "all", then copied. I merged the two layers, resulting in one layer named "Layer" showing a yellow area flanked by white. I then made a new mask. Doing this forces me to choose a mask type. Not understanding image editing very well, I left "Layer's mask" selected and made the mask. I then clicked the mask, pasted, then anchored the top layer. I then right clicked the one layer left and chose "apply mask". I then exported, keeping the original name (Gimp doesn't support DDS, but thankfully, the images I am using are PNG's and the CAW reads them as such). I then attempted to simply move the road. Still turns white at a distance. I tried re-editing to change the image used, then switch back. No luck. I even deleted the roads and replaced them. Still not luck!

Odd thing though: the original image only had the lines turn white at a distance. These new lines do the same, but any line crossing the screen horizontally is also white before the vertical ones:

How?

Found it out! It's fixed!

Okay, here is exactly what I did, in case others are still having a hard time with this. It is pretty much the same as in my previous post, which is almost the same as anamericanwaste's advice.

I open the file I want in Gimp
Note: When you open the program, you may not be able to see any of the toolbars. To fix this, click "Windows" on the top, then hover over "Dockable Dialogs" and click the ones that you want. For this, you will need "Layers", "Colors", and "Tool Presets"'. Once these are all open, just move them into a side area, like so:


Now, go find your image you want to fix. The CAW textures are located in Documents/Electronic Arts/The Sims 3 Create A World/UserToolData/SourceTextures.
If you have no custom textures and want to fix the vanilla road lines, it will be in this folder, labeled streeTile_stripes.dds. This will require a Gimp DDS Plugin
In my case, I am now going to navigate from here into /02. Street Detail/03. No Outer Lines/02. All Yellow/no-sides_double_continuous.png (one of those custom textures linked in my original post). I can just drag-drop it into Gimp:


From here, I create a new layer, leaving it named "Layer" (you can name it whatever you want) and I move the new layer below the original.

While on the top layer, use the eyedropper tool to copy the yellow of the middle lines (or alternatively just select a yellow color from the colors window)
Now, I select the new layer, then use the box selection tool to select an area covering the middle. Use the fill tool (looks like a bucket) and fill that selection with the yellow. Now click on "select" on the top (near to where we clicked on "Windows" earlier to get our tools, layers, and colors) and click "none" to deselect everything. Now use the colors window to get a basic white, and use the fill tool to fill in the areas at the sides that were left uncovered by the yellow. We should now have something like this:


Now, go back to the original layer, right click it in the Layers window, and select "Add Mask", chose "Layer's Alpha Channel" and click "Add". Now click the new area to the right of the layer's thumbnail image. This is the mask. Then click on "Select" at the top, then "All". Then copy it (CTRL + C). Now merge the layers. This will create a new layer from the two, simply named "Layer" (or whatever you called your new layer at the start).


Again, now on this new layer, make a mask, again choosing "Layer's Alpha Channel".
Click on that mask, then paste (CTRL + V). This will create a new "layer" but you are locked to it:


Right click this new layer, then select "Anchor Layer".

You now have an image that looks identical to the start.
Now, click "File" in the top left. Then "Export As". If you want, you can keep it named as it was when you first opened it, overwriting the base file. If it was a DDS, select BC3/DTX5 as the type of DDS. The images I am editing from the custom roads pack are all in PNG, so I simply save it as PNG and done. Gimp has a slider labeled "Compression Level", which it tries to set to 9 by default. I don't know what this is, but I set it to 0, and it worked.

I have been doing this with CAW open, and I have only been able to get the textures fixed after closing and reopening CAW.
Hope this is easy for everyone to understand, and thank you very much to @anamericanwaste with helping me when I first made this thread!