I think this is true, and I wish I could XP your post.How the imagined content in the game changes in 4E as the characters gain levels isn't quite the same as it is in 3E. I am not going to pretend to have a good grasp of how this works in either system, but my gut says: in 4E the group defines the colour of their campaign as they play it; in 3E it's established when the campaign begins.
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In 4E, I think the relationship between colour and the reward system changes: you don't know what it will mean, when you first start playing, to make a Hard Level 30 Acrobatics check. Which means that gaining levels doesn't have a defined relationship with what your PC can do in the fiction - just because your Acrobatics check has increased by 1, it doesn't mean you're that much closer to balancing on a cloud. I think the group needs to define that for themselves; as far as I can tell, this is supposed to arise organically through play, and go through major shifts as Paragon Paths and Epic Destinies enter the game.
This comes up again and again in my campaign - players doing stuff with skills, and with powers, that require adjudication based not on a preset correlation of particular tasks to particular DCs, but on exptrapolation from the fictional possibilities already established in play.
A recent example I posted about was the dwarf fighter-cleric making a Hard 16th level Endurance check to hold Whelm stead within a furnace so that his dwarven artificers could grab it with their tongs, preparatory to reforging it as Overwhelm. There is nothing in the DC charts that tells us that this is the sort of thing a paragorn warpriest does by using Endurnace. It emerges out of play. (I think of it as something like the rule in HeroQuest revised that the GM has to impose genre logic on declared actions before then allowing them to proceed to resolution - so even if a PC has Fast Runner 17 and a Horse Modest Galloper 12, it doesn't necessarily follow that the PC can make a check to outrun the horse.)
I think these elements of 4e are utlimately flaws in its design. The game works best when the DC chart is used - this is what the pacing and dynamics of the game are balanced around - but all those "simulationist" DC tables require you to read back from the level-appropriate DCs to particular story elements. They're a needless constraint, in my view, and in the case of the jumping rules create too much of an incentive to design a range of jumping utitlity powers that ultimately I think should all just be handled as bonuses to Athletics (just like the social utility powers grant bonuses to Diplomacy) - although arguably the relationship between jumping ability and the grid requires something less abstract here - which just highlight another of 4e's weaker points, namely, it's lack of smooth integration of its combat and non-combat resolution systems.4E's DC chart is based on what would be a challenge for you at that level. It does not determine that everything you encounter will be a challenge for you at that level. An oak door is an oak door, but a DM who wants to make a door that is hard to break isn't going to use an oak door at level 24. Similarly, specific tasks often have a set DC. The DC to jump a certain distance does not change with level, nor does the DC to heal someone. The DC to cure a disease is determined by the level of the disease. The DC to hear a loud noise at a certain distance through a stone wall does not change with level.