Are tru-tones too warm to show up against a mansard roof?

That's normal for tru-tones, especially on a dark house. Warm filament-style bulbs put out noticeably less light than cool white LEDs, and your paint color is eating a lot of what's left. Dark greenish gray absorbs light instead of bouncing it back, so the wall behind the bulbs gives you nothing to work with. On a light brick or cream-colored house, the wall itself acts like a reflector and the whole roofline glows. On yours, the bulbs are basically floating on a black backdrop at dusk, so they read as faint little dots unless you're close.

A few things worth checking before you give up on them. First, spacing. If you clipped the C9s a foot and a half or two apart on the roofline, tighten that up to about a foot. Density matters more than brightness for visibility from down the street, and warm bulbs especially need to run close together to read as a line instead of scattered points. Second, check what wattage or lumen rating you bought. Tru-tones come in different brightness levels and the big box store versions tend to be on the dimmer end.

On the porch, the smaller bulbs over a dark walkway are almost invisible, that's just physics. If you want the porch to register at all, either go up to C9s there too or add some greenery or garland under the railing so the light has something to catch.

As for whether warm works on a dark house, it can, but you have to commit. My place is a deep slate blue and I run warm bulbs on the rooflines and columns. Mine didn't really pop until I doubled the strand density and bumped up the bulb brightness on the second year. Now it looks like a candlelit photograph from down the block, which honestly reads better than the ice-blue houses to my eye. If after densifying you still can't see it from three houses down, then yeah, you've got a call to make. But give the tighter spacing a shot first, it's the cheapest fix and usually the one that actually solves it.

Don't judge them at dusk, that's honestly the worst possible time to look. I've got warm bulbs on a brick colonial and around 5pm they look washed out and weak, but once it's fully dark they come alive. Dusk has enough ambient light to compete with but not enough to show the house details, so everything kinda flattens out. Go check yours at 9pm some night before you change a thing. Also second what was said about spacing, I run mine tight on the roofline and it makes a huge difference from the street.

I'd push back on the spacing advice in the first reply. I ran warm bulbs on our dark brown siding and doubled up the strands the second year like they suggest, and all it did was turn faint dots into a long faint line. Same distance problem. What actually fixed it was swapping in higher output warm bulbs the next season, same warm look but you can finally see the roofline from the corner. Density helps but if the bulbs themselves are weak you're just packing dimness closer togather. Worth checking the box ratings before you spend a weekend re-clipping everthing.

Check wether you bought the ceramic-coated ones or the clear glass versions. The ceramic tru-tones have that soft painted look up close but they throw way less light down the street. I ran ceramic bulbs on my own fascia one year and swapped to clear warm glass the next, same color family, and the clear ones read maybe twice as far. Big difference nobody expects untill they see it side by side. If yours are ceramic and you love the look, keep them on the porch and put clear ones up top. The mixed setup looks intentional and solves the visibility problem without going cool white.

Update: waited for full dark like one reply suggested and they do look better once the sky's completley black, so dusk was definately part of my problem. Then I checked the box and sure enugh, mine are the ceramic coated ones, wich explains the rest. Question though, those higher output warm bulbs, are they the same C9 base? Hoping I can just swap them into the clips I allready put up.